SIRNA THERAPEUTICS, INC. Issuer and

EXHIBIT 4.18

SIRNA THERAPEUTICS, INC.

Issuer

and

AS DEPOSITARY

and

HOLDERS OF DEPOSITARY RECEIPTS

DEPOSIT AGREEMENT

Dated as of

[ __________________ ]

TABLE OF CONTENTS


ARTICLE I	DEFINITIONS	1

ARTICLE II	FORM OF RECEIPTS, DEPOSIT OF STOCK, EXECUTION AND DELIVERY, TRANSFER, SURRENDER AND REDEMPTION AND REPURCHASE OF RECEIPTS	2
Section 2.1	Form and Transfer of Receipts	2
Section 2.2	Deposit of Stock; Execution and Delivery of Receipts in Respect Thereof	3
Section 2.3	Redemption and Repurchase of Stock	4
Section 2.4	Register of Transfer of Receipts	5
Section 2.5	Combination and Split-ups of Receipts	5
Section 2.6	Surrender of Receipts and Withdrawal of Stock	5
Section 2.7	Limitations on Execution and Delivery, Transfer, Split-up, Combination and Surrender of Receipts and Withdrawal or Deposit of Stock	6
Section 2.8	Lost Receipts, etc	6
Section 2.9	Cancellation and Destruction of Surrendered Receipts	6
Section 2.10	Conversion	6

ARTICLE III	CERTAIN OBLIGATIONS OF HOLDERS OF RECEIPTS AND THE COMPANY	7
Section 3.1	Filing Proofs, Certificates and Other Information	7
Section 3.2	Payment of Taxes or Other Governmental Charges	7
Section 3.3	Withholding	8
Section 3.4	Representations and Warranties as to Stock	8

ARTICLE IV	THE STOCK, NOTICES	8
Section 4.1	Cash Distributions	8
Section 4.2	Distributions Other Than Cash	8
Section 4.3	Subscription Rights, Preferences or Privileges	9
Section 4.4	Notice of Dividends, Fixing of Record Date for Holders of Receipts	9
Section 4.5	Voting Rights	9
Section 4.6	Changes Affecting Stock and Reclassifications, Recapitalizations, etc	10
Section 4.7	Reports	10
Section 4.8	Lists of Receipt Holders	10

ARTICLE V	THE DEPOSITARY, THE DEPOSITARY’S AGENTS, THE REGISTRAR AND THE COMPANY	10
Section 5.1	Maintenance of Offices, Agencies, Transfer Books by the Depositary; the ▇▇▇▇▇▇▇▇▇	▇▇
Section 5.2	Prevention or Delay in Performance by the Depositary, the Depositary’s Agents, the Registrar or the Company	11
Section 5.3	Obligations of the Depositary, the Depositary’s Agents, the Registrar and the Company	11
Section 5.4	Resignation and Removal of the Depositary, Appointment of Successor Depositary	12
Section 5.5	Corporate Notices and Reports	12
Section 5.6	Deposit of Stock by the Company	12
Section 5.7	Indemnification by the Company	13


Section 5.8	Fees, Charges and Expenses	13

ARTICLE VI	AMENDMENT AND TERMINATION	13
Section 6.1	Amendment	13
Section 6.2	Termination	13

ARTICLE VII	MISCELLANEOUS	13
Section 7.1	Counterparts	13
Section 7.2	Exclusive Benefits of Parties	14
Section 7.3	Invalidity of Provisions	14
Section 7.4	Notices	14
Section 7.5	Depositary’s Agents	14
Section 7.6	Holders of Receipts Are Parties	14
Section 7.7	Governing Law	14
Section 7.8	Headings	15

DEPOSIT AGREEMENT

DEPOSIT AGREEMENT, dated as of [ ] among Sirna Therapeutics, Inc., a Delaware corporation, [ ], a under the laws of the State of [ ], as Depositary, and all holders from time to time of Receipts issued hereunder.

W I T N E S S E T H:

WHEREAS, the Company desires to provide as hereinafter set forth in this Deposit Agreement, for the deposit of shares of the Stock with the Depositary, as agent for the holders of the Receipts evidencing Depositary Shares representing an interest in the Stock so deposited, for the purposes set forth in this Deposit Agreement and for the issuance hereunder of such Receipts; and

WHEREAS, the Receipts are to be substantially in the form annexed as Exhibit A to this Deposit Agreement, with appropriate insertions, modifications and omissions to reflect the terms of any Certificate of Designation and otherwise, as hereinafter provided in this Deposit Agreement.

NOW, THEREFORE, in consideration of the premises contained herein, it is agreed by and among the parties hereto as follows:

ARTICLE I

DEFINITIONS

The following definitions shall apply to the respective terms (in the singular and plural forms of such terms) used in this Deposit Agreement and the Receipts:

“CERTIFICATE OF DESIGNATION” shall mean the Certificate of Designation establishing and setting forth the rights, preferences, privileges, limitations and restrictions of the Stock, as filed with the Secretary of State of the State of Delaware.

“CERTIFICATE OF INCORPORATION” shall mean the Amended and Restated Certificate of Incorporation, as amended or as amended and restated from time to time, of the Company.

“COMPANY” shall mean Sirna Therapeutics, Inc., a Delaware corporation, and its successors.

“CORPORATE OFFICE” shall mean the office of the Depositary in [ ], at which at any particular time its business in respect of matters governed by this Deposit Agreement shall be administered, which at the date of this Deposit Agreement is located at [ ] .

“DEPOSIT AGREEMENT” shall mean this agreement, as the same may be amended, modified or supplemented from time to time to reflect the terms of any Certificate of Designation or otherwise in accordance with the provisions hereof.

“DEPOSITARY” shall mean [ ], as Depositary hereunder, and any successor as Depositary hereunder.

“DEPOSITARY SHARE” shall mean the rights evidenced by the Receipts executed and delivered hereunder, including the interests in Stock granted to holders of Receipts pursuant to the terms and conditions of the Deposit Agreement. Each Depositary Share shall represent an interest in [ ] of one share of Stock deposited with the Depositary hereunder and the same proportionate interest in any and all other property received by the Depositary in respect of such share of Stock and held under this Deposit Agreement. Subject to the terms of this Deposit Agreement, each record holder of a Receipt evidencing a Depositary Share or Shares is entitled,

proportionately, to all the rights, preferences and privileges, and subject to all the qualifications and restrictions, of the Stock represented by such Depositary Share or Shares, including any dividend, voting, conversion, redemption, liquidation and sinking fund rights contained in the Certificate of Designation, and to the benefits of all obligations and duties of the Company in respect of the Stock under the Certificate of Designation and the Certificate of Incorporation.

“DEPOSITARY’S AGENT” shall mean an agent appointed by the Depositary as provided, and for the purposes specified, in Section 7.5.

“RECEIPT” shall mean a Depositary Receipt executed and delivered hereunder, in substantially the form of Exhibit A hereto, evidencing a Depositary Share or Shares, as the same may be amended from time to time to reflect the terms of any Certificate of Designation or otherwise in accordance with the provisions hereof.

“RECORD HOLDER” or “HOLDER” as applied to a Receipt shall mean the person in whose name a Receipt is registered on the books maintained by or on behalf of the Depositary for such purpose.

“REGISTRAR” shall mean any company appointed to register ownership and transfers of Receipts as herein provided.

“SECURITIES ACT” shall mean the Securities Act of 1933, as amended.

“STOCK” shall mean shares of the Company’s Preferred Stock, Series [ ], par value $0.01 per share.

ARTICLE II

FORM OF RECEIPTS, DEPOSIT OF STOCK, EXECUTION AND DELIVERY,

TRANSFER, SURRENDER AND REDEMPTION AND REPURCHASE OF RECEIPTS

SECTION 2.1 FORM AND TRANSFER OF RECEIPTS. Receipts shall be engraved or printed or lithographed unless they are evidenced by a global receipt held by a depositary for a clearing system and shall be substantially in the form set forth in Exhibit A annexed to this Deposit Agreement, with appropriate insertions, modifications and omissions to reflect the terms of any Certificate of Designation or otherwise, as hereinafter provided. Receipts shall be executed by the Depositary by the manual signature of a duly authorized officer of the Depositary; provided, however, that such signature may be a facsimile if a Registrar (other than the Depositary) shall have countersigned the Receipts by manual signature of a duly authorized officer of the Registrar. Pending the preparation of definitive Receipts, the Depositary, upon the written order of the Company delivered in accordance with Section 2.2, shall execute and deliver temporary Receipts which shall be printed, lithographed, typewritten, or otherwise reproduced substantially of the tenor of the definitive Receipts in lieu of which they are issued and with appropriate insertions, modifications, omissions, substitutions and other variations as the persons executing such Receipts may determine are necessary for such temporary Receipts, as evidenced by their execution of such temporary Receipts. If temporary Receipts are issued, the Company and the Depositary will cause definitive Receipts to be prepared without unreasonable delay; provided that if such temporary Receipts are global Receipts held by a depositary for a clearing system, definitive Receipts need not be prepared until the Receipts cease to be so held. After the preparation of definitive Receipts, the temporary Receipts shall be exchangeable for definitive Receipts upon surrender of the temporary Receipts at the Corporate Office or such other office as the Depositary may designate, without charge to the holder. Upon surrender for cancellation of any one or more temporary Receipts, the Depositary shall execute and deliver in exchange therefore definitive Receipts representing the same number of Depositary Shares as represented by the surrendered temporary Receipt or Receipts. Such exchange shall be made at the Company’s expense and without any charge therefore. Until so exchanged, the temporary Receipts shall in all respects be entitled to the same benefits under this Deposit Agreement, and with respect to the Stock, as definitive Receipts.

No Receipt shall be entitled to any benefits under this Deposit Agreement or be valid or obligatory for any purpose unless it shall have been executed as provided in the preceding paragraph.

The Depositary shall record on its books each Receipt executed as provided above and delivered as hereinafter provided. Receipts bearing the facsimile signature of anyone who was at any time a duly authorized officer of the Depositary shall bind the Depositary, notwithstanding that such officer has ceased to hold such office prior to the delivery of such Receipts.

Receipts may be issued in denominations of any number of whole Depositary Shares. All Receipts shall be dated the date of their execution.

Receipts may be endorsed with or have incorporated in the text thereof such legends or recitals or changes not inconsistent with the provisions of this Deposit Agreement as may be required by the Depositary or required to comply with any applicable law or regulation or with the rules and regulations of any securities exchange upon which the Stock or the Depositary Shares may be listed or to conform with any usage with respect thereto, or to indicate any special limitations or restrictions to which any particular Receipts are subject by reason of the date of issuance of the Stock or otherwise.

Title to any Receipt (and to the Depositary Shares evidenced by such Receipt) that is properly endorsed or accompanied by a properly executed instrument of transfer shall be transferable by delivery with the same effect as in the case of investment securities in general; provided, however, that the Depositary may, notwithstanding any notice to the contrary, treat the record holder thereof at such time as the absolute owner thereof for the purpose of determining the person entitled to distributions of dividends or other distributions or to any notice provided for in this Deposit Agreement and for all other purposes.

SECTION 2.2 DEPOSIT OF STOCK; EXECUTION AND DELIVERY OF RECEIPTS IN RESPECT THEREOF. Subject to the terms and conditions of this Deposit Agreement, the Company or any holder of Stock may deposit such Stock under this Deposit Agreement by delivery to the Depositary of a certificate or certificates for the Stock to be deposited, properly endorsed or accompanied, if required by the Depositary, by a properly executed instrument of transfer in form satisfactory to the Depositary, together with (i) all such certifications as may be required by the Depositary in accordance with the provisions of this Deposit Agreement and (ii) a written order of the Company or such holder, as the case may be, directing the Depositary to execute and deliver to or upon the written order of the person or persons stated in such order a Receipt or Receipts for the number of Depositary Shares representing such deposited Stock.

Upon receipt by the Depositary of a certificate or certificates for Stock to be deposited hereunder, together with the other documents specified above, the Depositary shall, as soon as transfer and registration can be accomplished, present such certificate or certificates to the registrar and transfer agent of the Stock for transfer and registration in the name of the Depositary or its nominee of the Stock being deposited. Deposited Stock shall be held by the Depositary in an account to be established by the Depositary at the Corporate Office.

Upon receipt by the Depositary of a certificate or certificates for Stock to be deposited hereunder, together with the other documents specified above, the Depositary, subject to the terms and conditions of this Deposit Agreement, shall execute and deliver, to or upon the order of the person or persons named in the written order delivered to the Depositary referred to in the first paragraph of this Section 2.2, a Receipt or Receipts for the number of whole Depositary Shares representing the Stock so deposited and registered in such name or names as may be requested by such person or persons. The Depositary shall execute and deliver such Receipt or Receipts at the Corporate Office, except that, at the request, risk and expense of any person requesting such delivery and for such person’s account or, upon the order of such person, any other person’s account, such delivery may be made at such other place as may be designated by such person. In each case, delivery will be made only upon payment to the Depositary of all taxes and other governmental charges and any fees payable in connection with such deposit and the transfer of the deposited Stock.

The Company shall deliver to the Depositary from time to time such quantities of Receipts as the Depositary may request to enable the Depositary to perform its obligations under this Deposit Agreement.

SECTION 2.3 REDEMPTION AND REPURCHASE OF STOCK. Whenever the Company shall redeem shares of Stock in accordance with a Certificate of Designation, it shall (unless otherwise agreed in writing with the Depositary) give the Depositary in its capacity as Depositary not less than 3 business days’ prior notice of the proposed date of the mailing of a notice of redemption of Stock and the simultaneous redemption of the Depositary Shares representing the Stock to be redeemed and of the number of such shares of Stock held by the Depositary to be redeemed. Unless the Certificate of Designation for a specific series of Stock provides for a different notice period with respect to that Stock in the event of its redemption, the Depositary shall, as directed by the Company in writing, mail, first class postage prepaid, notice of the redemption of Stock and the proposed simultaneous redemption of the Depositary Shares representing the Stock to be redeemed not less than 30 and not more than 60 days prior to the date fixed for redemption of such Stock and Depositary Shares, to the record holders of the Receipts evidencing the Depositary Shares to be so redeemed at the addresses of such holders as the same appear on the records of the Depositary or any Depositary’s Agent or Registrar. Notwithstanding the foregoing, neither failure to mail or publish any such notice to one or more such holders nor any defect in any notice shall affect the sufficiency of the proceedings for redemption. The Company shall provide the Depositary with such notice, and each such notice shall state the method for determining the amount payable per Depositary Share, the redemption date, and the number of Depositary Shares to be redeemed, and such notice shall call upon each holder of Depositary Shares to surrender, on the redemption date and at the place or places designated by the Company, the Receipts evidencing Depositary Shares to be redeemed. On the date of any such redemption the Depositary shall surrender the certificate or certificates held by the Depositary evidencing the number of shares of Stock to be redeemed in the manner specified in the notice of redemption of Stock provided by the Company pursuant to the applicable Certificate of Designation. The Depositary shall, thereafter, redeem the number of Depositary Shares representing such redeemed Stock upon the surrender of Receipts evidencing such Depositary Shares in the manner provided in the notice sent to record holders of Receipts.

Notice having been mailed by the Depositary as aforesaid, from and after the redemption date (unless the Company shall have failed to redeem the shares of Stock to be redeemed by it upon the surrender of the certificate or certificates therefore by the Depositary as described in the preceding paragraph), the Depositary Shares called for redemption shall be deemed no longer to be outstanding and all rights of the holders of Receipts evidencing such Depositary Shares (except the right to receive the cash, securities or other property payable upon redemption upon surrender of such Receipts) shall, to the extent of such Depositary Shares, cease and terminate. The foregoing shall be subject further to the terms and conditions of the applicable Certificate of Designation.

If fewer than all the Depositary Shares are to be redeemed, the Depositary Shares to be redeemed will be selected by lot or proportionately, as may be determined by the Depositary. If fewer than all of the Depositary Shares evidenced by a Receipt are called for redemption, the Depositary will deliver to the holder of such Receipt upon its surrender to the Depositary, cash, securities or other property payable upon redemption in respect of the Depositary Shares called for redemption and a new Receipt evidencing the Depositary Shares evidenced by such prior Receipt and not called for redemption.

The Depositary shall not be required to transfer or exchange for another Receipt any Receipt evidencing Depositary Shares called or being called for redemption, in whole or in part except as provided in the immediately preceding paragraph of this Section 2.3.

Whenever the Company shall be required to make an offer to repurchase Depositary Shares representing Stock in accordance with a Certificate of Designation, it shall (unless otherwise agreed in writing with the Depositary) give the Depositary in its capacity as Depositary not less than 3 business days’ prior notice of the required date of the mailing of a notice of the repurchase offer. The Depositary shall, as directed by the Company in writing, mail, first class postage prepaid, notice of the relevant terms of the repurchase offer, as provided by the Company, to the record holders of the Receipts at the addresses of such holders as the same appear on the records of the Depositary or any Depositary’s Agent or Registrar, including: (i) that such notice is being given pursuant to a repurchase offer, (ii) the number of Depositary Shares and Stock for which the offer is being made, (iii) the method for determining the amount payable per Depositary Share, (iv) the last date, which, unless the Certificate of Designation for a specific series of Stock provides for a different period with respect to that Stock in the event that the Company is required to make an offer to repurchase it, shall not be less than 30 nor more than 60 days after the date of such notice, by which a holder must elect to accept the repurchase offer, (v) the procedures that such holder must follow to exercise its rights, and (vi) the procedures for withdrawing an election.

The Depositary shall, thereafter, receive from each holder electing to have Depositary Shares repurchased pursuant to the repurchase offer in accordance with the instructions in the notice, the holder’s Receipts, with an appropriate form duly completed prior to the repurchase date. Holders will be entitled to withdraw an election by a written notice of withdrawal delivered to the Depositary prior to the close of business on the repurchase date. The notice of withdrawal shall state the number of Depositary Shares and the Receipt numbers to which the notice of withdrawal relates and the number of Depositary Shares and Receipt numbers, if any, which remain subject to election. In case the aggregate number of Depositary Shares offered for repurchase by the holders exceeds the amount of Depositary Shares which the Company has offered to repurchase pursuant to the repurchase offer, the Depositary Shares to be repurchased shall be selected by the Depositary by lot or proportionately, as may be determined by the Depositary. The Depositary shall, at the direction of the Company, cause payment to be mailed or delivered to each tendering holder as promptly as reasonably practicable after the repurchase date, in the amount of the repurchase price for the Depositary Shares tendered, and any unpurchased Depositary Shares to be returned to the holder thereof. The foregoing is subject further to the terms and conditions of the applicable Certificate of Designation.

SECTION 2.4 REGISTER OF TRANSFER OF RECEIPTS. Subject to the terms and conditions of this Deposit Agreement, the Depositary shall register on its books from time to time transfers of Receipts upon any surrender thereof at the Corporate Office, or such other office as the Depositary may designate for such purpose, by the record holder in person or by a duly authorized attorney, properly endorsed or accompanied by a properly executed instrument of transfer, together with evidence of the payment of any transfer taxes as may be required by law. Upon such surrender, the Depositary shall execute a new Receipt or Receipts and deliver the same to or upon the order of the person entitled thereto evidencing the same aggregate number of Depositary Shares evidenced by the Receipt or Receipts surrendered.

SECTION 2.5 COMBINATION AND SPLIT-UPS OF RECEIPTS. Upon surrender of a Receipt or Receipts at the Corporate Office, or such other office as the Depositary may designate for the purpose of effecting a split-up or combination of Receipts, subject to the terms and conditions of this Deposit Agreement, the Depositary shall execute and deliver a new Receipt or Receipts in the authorized denominations requested evidencing the same aggregate number of Depositary Shares evidenced by the Receipt or Receipts surrendered; provided, however, that the Depositary shall not issue any Receipt evidencing a fractional Depositary Share.

SECTION 2.6 SURRENDER OF RECEIPTS AND WITHDRAWAL OF STOCK. Any holder of a Receipt, including the Company, shall have the right, upon payment of any amount due to the Depositary with respect to the Receipt, to withdraw any or all of the Stock (but only in whole shares of Stock) represented by the Depositary Shares and all money and other property, if any, represented by such Depositary Shares by surrendering the Receipt or Receipts evidencing such Depositary Shares at the Corporate Office, or at such other office as the Depositary may designate for such withdrawals (and cancellation of the surrendered Receipts as provided in Section 2.9). After such surrender, without unreasonable delay, the Depositary shall deliver to the holder the whole number of shares of Stock and all such money and other property, if any, represented by the Depositary Shares evidenced by the Receipt or Receipts so surrendered for withdrawal. If the Receipt or Receipts delivered by the holder to the Depositary in connection with such withdrawal shall evidence a number of Depositary Shares in excess of the number of whole Depositary Shares representing the whole number of shares of Stock to be withdrawn, the Depositary shall at the same time, in addition to such whole number of shares of Stock and such money and other property, if any, to be withdrawn, deliver to the holder, or (subject to Section 2.4) upon its order, a new Receipt or Receipts evidencing such excess number of whole Depositary Shares.

Delivery of the Stock and such money and other property being withdrawn may be made by the delivery of such certificates, documents of title and other instruments as the Depositary may deem appropriate, which, if required by the Depositary, shall be properly endorsed or accompanied by proper instruments of transfer.

The Depositary shall deliver the Stock and the money and other property, if any, represented by the Depositary Shares evidenced by Receipts surrendered for withdrawal, without unreasonable delay, at the office at which such Receipts were surrendered, except that, at the request, risk and expense of the Company such delivery may be made, without unreasonable delay, at such other place as may be designated by the Company.

For purposes of determining the number of Depositary Shares outstanding on any dividend payment date, the Receipts representing Depositary Shares acquired by the Company on or prior to such dividend payment date and not theretofore delivered to the Depositary for withdrawal and cancellation shall be deemed to be outstanding.

SECTION 2.7 LIMITATIONS ON EXECUTION AND DELIVERY, TRANSFER, SPLIT-UP, COMBINATION AND SURRENDER OF RECEIPTS AND WITHDRAWAL OR DEPOSIT OF STOCK. As a condition precedent to the execution and delivery, registration of transfer, split-up, combination, or surrender of any Receipt, the delivery of any distribution thereon or withdrawal or deposit of Stock, or the exercise of any conversion right referred to in Section 2.10, the Depositary, any of the Depositary’s Agents, the Registrar or the Company may require any or all of the following: (i) payment to it of a sum sufficient for the payment (or, in the event that the Depositary or the Company shall have made such payment, the reimbursement to it) of any tax or other governmental charge or fee with respect thereto (including any such tax or charge or fee with respect to the Stock being deposited or the Stock being withdrawn or with respect to property of the Company being issued upon redemption or conversion); (ii) production of proof satisfactory to it as to the identity and genuineness of any signature; and (iii) compliance with such reasonable regulations, if any, as the Depositary or the Company may establish not inconsistent with the provisions of this Deposit Agreement.

The deposit of Stock may be refused, or the registration of transfer, split-up, combination or surrender of outstanding Receipts and the withdrawal of deposited Stock or the exercise of any conversion right referred to in Section 2.10 may be suspended (i) during any period when the register of stockholders of the Company is closed, (ii) if any such action is deemed necessary or advisable by the Depositary, any of the Depositary’s Agents or the Company at any time or from time to time because of any requirement of law or of any government or governmental body or commission, or under any provision of this Deposit Agreement, or (iii) with the approval of the Company, for any other reason. Without limitation of the foregoing, the Depositary shall not knowingly accept for deposit under this Deposit Agreement any shares of Stock that are required to be registered under the Securities Act unless a registration statement under the Securities Act is in effect as to such shares of Stock.

SECTION 2.8 LOST RECEIPTS, ETC. In case any Receipt shall be mutilated or destroyed or lost or stolen, the Depositary shall execute and deliver a Receipt of like form and tenor in exchange and substitution for such mutilated Receipt or in lieu of and in substitution for such destroyed, lost or stolen Receipt unless the Depositary has notice that such Receipt has been acquired by a bona fide purchaser; provided, however, that the holder thereof provides the Depositary with (i) evidence satisfactory to the Depositary of such destruction, loss or theft of such Receipt, of the authenticity thereof and of his ownership thereof, (ii) reasonable indemnification satisfactory to the Depositary or the payment of any charges incurred by the Depositary in obtaining insurance in lieu of such indemnification and (iii) payment of any expense (including fees, charges and expenses of the Depositary) in connection with such execution and delivery.

SECTION 2.9 CANCELLATION AND DESTRUCTION OF SURRENDERED RECEIPTS. All Receipts surrendered to the Depositary or any Depositary’s Agent shall be cancelled by the Depositary. Except as prohibited by applicable law or regulation, the Depositary is authorized to destroy such Receipts so canceled.

SECTION 2.10 CONVERSION. In the event that the Stock, in accordance with its Certificate of Designation, is convertible into the Company’s common stock or other securities, subject to the terms and conditions of this Deposit Agreement, a holder of a Receipt or Receipts may surrender such Receipt or Receipts at the Corporate Office or at such other office or to a Depositary’s Agent that the Depositary may designate for such purpose, together with a notice of conversion duly completed and executed, thereby directing the Depositary or such Depositary’s Agent to instruct the Company to cause the conversion of the number of shares of Stock specified in such notice of conversion into shares of the Company’s common stock or other securities at the rate specified in the applicable Certificate of Designation, and an assignment of such Receipt or Receipts to the Company or in blank, duly completed and executed, along with any other documents or instruments and any amounts required by the applicable Certificate of Designation.

Upon receipt by the Depositary or a Depositary’s Agent of a Receipt or Receipts, together with a notice of conversion, duly completed and executed, directing the Depositary or such Depositary’s Agent to instruct the Company to cause the conversion of a specified number of shares of Stock at the rate specified in the applicable Certificate of Designation, and an assignment of such Receipt or Receipts to the Company or in blank, duly

completed and executed, along with any other documents or instruments or amounts referred to in the preceding paragraph, the Depositary or such Depositary’s Agent shall instruct the Company, subject to any adjustment provided for in the applicable Certificate of Designation, (i) to cause the conversion at the rate specified in the applicable Certificate of Designation of the number of shares of Stock represented by the Depositary Shares evidenced by the Receipt or Receipts so surrendered for conversion as specified in the written notice to the Depositary or such Depositary’s Agent and (ii) to cause the delivery to the holder of such Receipt or Receipts of (a) a certificate or certificates evidencing the number of whole shares of the Company’s common stock or other securities into which such Stock has been converted, and (b) the amount of cash or other property, if any, to which such holder is entitled in lieu of fractional shares of, or fractional interests in, the Company’s common stock or other securities otherwise deliverable by the Company upon such conversion, calculated in accordance with the applicable Certificate of Designation. The Company shall as promptly as practicable after receipt thereof cause the delivery of the certificate or certificates and cash or other property, if any, referred to in clauses (a) and (b) above, and such conversion shall be deemed to have been effected immediately prior to the close of business on the date of such receipt and shall occur at the rate specified in the Certificate of Designation in effect at such time and on such date. Upon such conversion, the Depositary or such Depositary’s Agent (i) shall deliver to the holder a Receipt evidencing the number of Depositary Shares evidenced by the surrendered Receipt or Receipts in excess of the number of Depositary Shares evidenced by such Receipt or Receipts that have been so converted, (ii) shall cancel the Receipts surrendered for conversion and (iii) shall deliver to the Company for cancellation the number of shares of Stock evidenced by the Receipts so surrendered and so converted. Upon the delivery of the shares of Stock to be cancelled due to such conversion by the Depositary or such Depositary’s Agent to the Company, the Company shall deliver to the Depositary or such Depositary’s Agent, as applicable, a certificate or certificates evidencing the number of shares of Stock, if any, that equals the excess of the number of shares evidenced by the surrendered certificate over the number of shares evidenced by that certificate that have been so converted. Depositary Shares converted in connection with conversion of the Stock represented thereby shall only be converted in whole, and not in part.

Upon the conversion of any Stock for which a notice of conversion has been provided to the Depositary or a Depositary’s Agent by the holder of the Receipt or Receipts representing such Stock, the Depositary Shares evidenced by such Receipt or Receipts shall be deemed no longer outstanding, all rights of the holder of the Receipt or Receipts evidencing such Depositary Shares (except the right to receive (i) the Company’s common stock or other securities to which such holder is entitled upon conversion in accordance with the applicable Certificate of Designation, (ii) any cash or other property payable in accordance with the applicable Certificate of Designation with respect to any fractional shares or other fractional interests in the Company’s common stock or other securities otherwise deliverable by the Company upon conversion, (iii) any Receipts evidencing Depositary Shares representing Stock which was not so converted and (iv) any other securities, property or cash to which such holder is entitled under this Deposit Agreement) shall cease and terminate, and the Receipt or Receipts evidencing such Depositary Shares shall be cancelled. No fractional shares or other fractional interests in the Company’s common stock or other securities shall be deliverable by the Company upon conversion of the Stock represented by the Depositary Shares.

ARTICLE III

CERTAIN OBLIGATIONS OF HOLDERS OF RECEIPTS AND THE COMPANY

SECTION 3.1 FILING PROOFS, CERTIFICATES AND OTHER INFORMATION. Any person presenting Stock for deposit or any holder of a Receipt may be required from time to time to file such proof of residence or other information, to execute such certificates and to make such representations and warranties as the Depositary or the Company may reasonably deem necessary or proper. The Depositary or the Company may withhold or delay the delivery of any Receipt, the registration of transfer or redemption of any Receipt, the withdrawal of the Stock represented by the Depositary Shares evidenced by any Receipt, the distribution of any dividend or other distribution or the exercise of any conversion right referred to in Section 2.10, or refuse to accept Receipts that are delivered for surrender, until such proof or other information is filed, such certificates are executed or such representations and warranties are made.

SECTION 3.2 PAYMENT OF TAXES OR OTHER GOVERNMENTAL CHARGES. If any tax or other governmental charge or fee shall become payable by or on behalf of the Depositary with respect to (i) any Receipt, (ii) the Depositary Shares evidenced by such Receipt, (iii) the Stock (or fractional interest therein) or other property represented by such Depositary Shares, or (iv) any transaction referred to in Section 4.6, such tax (including transfer,

issuance or acquisition taxes, if any) or governmental charge or fee shall be payable by the holder of such Receipt, who shall pay the amount thereof to the Depositary. Until such payment is made, registration or transfer of any Receipt or any split-up or combination thereof or any withdrawal of the Stock or money or other property, if any, represented by the Depositary Shares evidenced by such Receipt or Receipts delivered for surrender or the exercise of any conversion right referred to in Section 2.10 may be refused, any dividend or other distribution may be withheld and any part or all of the Stock or other property represented by the Depositary Shares evidenced by such Receipt may be sold for the account of the holder thereof (after attempting by reasonable means to notify such holder prior to such sale). Any dividend or other distribution so withheld and the proceeds of any such sale may be applied to any payment of such tax or other governmental charge or fee, the holder of such Receipt remaining liable for any deficiency.

SECTION 3.3 WITHHOLDING. The Depositary shall act as the tax withholding agent for any payments, distributions made with respect to the Depositary Shares and Receipts, and the Stock. The Depositary shall be responsible with respect to the Depositary Shares, Receipts and Stock for the timely (i) collection and deposit of any required withholding or backup withholding tax, and (ii) filing of any information returns or other documents with federal (and other applicable) taxing authorities.

SECTION 3.4 REPRESENTATIONS AND WARRANTIES AS TO STOCK. In the case of the initial deposit of the Stock, the Company and, in the case of subsequent deposits thereof, each person so depositing Stock under this Deposit Agreement shall be deemed thereby to represent and warrant that such Stock and each certificate therefore are valid and that the person making such deposit is duly authorized to do so. Such representations and warranties shall survive the deposit of the Stock and the issuance of Receipts therefor.

ARTICLE IV

THE STOCK, NOTICES

SECTION 4.1 CASH DISTRIBUTIONS. Whenever the Depositary shall receive any cash dividend or other cash distribution on the Stock (other than cash dividends or cash distributions paid by the Company in lieu of fractional shares or other fractional interests in the Company’s common stock or other securities otherwise deliverable by the Company in accordance with the applicable Certificate of Designation), the Depositary shall, subject to Section 3.2, distribute to record holders of Receipts on the record date fixed pursuant to Section 4.4 such amounts of such sum as are, as nearly as practicable, in proportion to the respective numbers of Depositary Shares evidenced by the Receipts held by such holders; provided, however, that in case the Company or the Depositary shall be required by law to withhold and does withhold from any cash dividend or other cash distribution in respect of the Stock an amount on account of taxes, the amount made available for distribution or distributed in respect of Depositary Shares shall be reduced accordingly. The Depositary shall distribute or make available for distribution, as the case may be, only such amount, however, as can be distributed without attributing to any holder of Depositary Shares a fraction of one cent and any balance not so distributable shall be held by the Depositary (without liability for interest thereon) and shall be added to and be treated as part of the next sum received by the Depositary for distribution to record holders of Receipts then outstanding.

SECTION 4.2 DISTRIBUTIONS OTHER THAN CASH. Whenever the Depositary shall receive any distribution other than cash, rights, preferences or privileges upon the Stock, the Depositary shall, subject to Section 3.2, distribute to record holders of Receipts on the record date fixed pursuant to Section 4.4 such amounts of the securities or property received by it as are, as nearly as practicable, in proportion to the respective numbers of Depositary Shares evidenced by the Receipts held by such holders, in any manner that the Depositary and the Company may deem equitable and practicable for accomplishing such distribution. If, in the opinion of the Company after consultation with the Depositary, such distribution cannot be made proportionately among such record holders, or if for any other reason (including any tax withholding or securities law requirement), the Depositary deems, after consultation with the Company, such distribution not to be feasible, the Depositary may, with the approval of the Company which approval shall not be unreasonably withheld, adopt such method as it deems equitable and practicable for the purpose of effecting such distribution, including the sale (at public or private sale) of the securities or property thus received, or any part thereof, at such place or places and upon such terms as it may deem proper. The net proceeds of any such sale shall, subject to Section 3.2, be distributed or made available for distribution, as the case may be, by the Depositary to record holders of Receipts as provided by Section 4.1 in the case of a distribution received in cash.

SECTION 4.3 SUBSCRIPTION RIGHTS, PREFERENCES OR PRIVILEGES. If the Company shall at any time offer or cause to be offered to the persons in whose names Stock is registered on the books of the Company any rights, preferences or privileges to subscribe for or to purchase any securities or any rights, preferences or privileges of any other nature, such rights, preferences or privileges shall in each such instance be made available by the Depositary to the record holders of Receipts in such manner as the Company shall instruct (including by the issue to such record holders of warrants representing such rights, preferences or privileges); provided, however, that (i) if at the time of issue or offer of any such rights, preferences or privileges the Company determines and instructs the Depositary that it is not lawful or feasible to make such rights, preferences or privileges available to some or all holders of Receipts (by the issue of warrants or otherwise) or (ii) if and to the extent instructed by holders of Receipts who do not desire to exercise such rights, preferences or privileges, the Depositary shall then, in each case, and if applicable laws or the terms of such rights, preferences or privileges so permit, sell such rights, preferences or privileges of such holders at public or private sale, at such place or places and upon such terms as it may deem proper. The net proceeds of any such sale shall be distributed by the Depositary to the record holders of Receipts entitled thereto as provided by Section 4.1 in the case of a distribution received in cash.

If registration under the Securities Act of the securities to which any rights, preferences or privileges relate is required in order for holders of Receipts to be offered or sold such securities, the Company shall promptly file a registration statement pursuant to the Securities Act with respect to such rights, preferences or privileges and securities and use its reasonable best efforts and take all steps reasonably available to it to cause such registration statement to become effective sufficiently in advance of the expiration of such rights, preferences or privileges to enable such holders to exercise such rights, preferences or privileges. In no event shall the Depositary make available to the holders of Receipts any right, preference or privilege to subscribe for or to purchase any securities unless and until such registration statement shall have become effective or unless the offering and sale of such securities to such holders are exempt from registration under the provisions of the Securities Act.

If any other action under the law of any jurisdiction or any governmental or administrative authorization, consent or permit is required in order for such rights, preferences or privileges to be made available to holders of Receipts, the Company agrees with the Depositary that the Company will use its reasonable best efforts to take such action or obtain such authorization, consent or permit sufficiently in advance of the expiration of such rights, preferences or privileges to enable such holders to exercise such rights, preferences or privileges.

SECTION 4.4 NOTICE OF DIVIDENDS, FIXING OF RECORD DATE FOR HOLDERS OF RECEIPTS. Whenever (i) any cash dividend or other cash distribution shall become payable, or any distribution other than cash shall be made, or any rights, preferences or privileges shall at any time be offered, with respect to the Stock, or (ii) the Depositary shall receive notice of any meeting at which holders of Stock are entitled to vote or of which holders of Stock are entitled to notice, or (iii) of any mandatory conversion of, or any election on the part of the Company to call for the redemption or exchange of, any shares of Stock, in accordance with the provisions of the applicable Certificate of Designation or otherwise, the Depositary shall in each such instance fix a record date (which shall be the same date as the record date fixed by the Company with respect to the Stock) for the determination of the holders of Receipts (x) who shall be entitled to receive such dividend, distribution, rights, preferences or privileges or the net proceeds of the sale thereof, or (y) who shall be entitled to give instructions for the exercise of voting rights at any such meeting or to receive notice of such meeting or of such conversion, exchange or redemption.

SECTION 4.5 VOTING RIGHTS. Upon receipt of notice of any meeting at which the holders of Stock are entitled to vote, the Depositary shall, as soon as practicable thereafter, mail to the record holders of Receipts a notice, which shall be provided by the Company and which shall contain (i) such information as is contained in such notice of meeting, (ii) a statement that the holders of Receipts at the close of business on a specified record date fixed pursuant to Section 4.4 will be entitled, subject to any applicable provision of law, the Certificate of Incorporation or the applicable Certificate of Designation, to instruct the Depositary as to the exercise of the voting rights pertaining to the Stock represented by their respective Depositary Shares and (iii) a brief statement as to the manner in which such instructions may be given. Upon the written request of a holder of a Receipt on such record date, the Depositary shall endeavor insofar as practicable to vote or cause to be voted the Stock represented by the Depositary Shares evidenced by such Receipt in accordance with the instructions set forth in such request. The

Company hereby agrees to take all reasonable action that may be deemed necessary by the Depositary in order to enable the Depositary to vote such Stock or cause such Stock to be voted. In the absence of specific instructions from the holder of a Receipt, the Depositary will abstain from voting to the extent of the Stock represented by the Depositary Shares evidenced by such Receipt.

SECTION 4.6 CHANGES AFFECTING STOCK AND RECLASSIFICATIONS, RECAPITALIZATIONS, ETC. Upon any split-up, consolidation or any other reclassification of Stock, or upon any recapitalization, reorganization, merger, amalgamation or consolidation affecting the Company or to which it is a party or sale of all or substantially all of the Company’s assets, the Depositary shall treat any shares of Stock or other securities or property (including cash) that shall be received by the Depositary in exchange for or in conversion of or in respect of the Stock as new deposited property under this Deposit Agreement, and Receipts then outstanding shall thenceforth represent the proportionate interests of holders thereof in the new deposited property so received in exchange for or in respect of such Stock. In any such case the Depositary may, in its discretion, with the approval of the Company, execute and deliver additional Receipts, or may call for the surrender of all outstanding Receipts to be exchanged for new Receipts specifically describing such new deposited property.

SECTION 4.7 REPORTS. The Company or, at the option of the Company, the Depositary shall forward to the holders of Receipts any reports and communications received from the Company that are received by the Depositary as the holder of Stock.

SECTION 4.8 LISTS OF RECEIPT HOLDERS. Promptly upon request from time to time by the Company, the Depositary shall furnish to it a list, as of a recent date, of the names, addresses and holdings of Depositary Shares of all persons in whose names Receipts are registered on the books of the Depositary, any Depositary’s Agent or the Registrar. At the expense of the Company, the Company shall have the right to inspect transfer and registration records of the Depositary, any Depositary’s Agent or the Registrar, take copies thereof and require the Depositary, any Depositary’s Agent or the Registrar to supply copies of such portions of such records as the Company may request.

ARTICLE V

THE DEPOSITARY, THE DEPOSITARY’S AGENTS, THE REGISTRAR AND THE COMPANY

SECTION 5.1 MAINTENANCE OF OFFICES, AGENCIES, TRANSFER BOOKS BY THE DEPOSITARY; THE REGISTRAR. Upon execution of this Deposit Agreement in accordance with its terms, the Depositary shall maintain (i) at the Corporate Office facilities for the execution and delivery, registration, registration of transfer, surrender, split-up, combination, redemption and conversion of Receipts and deposit and withdrawal of Stock, and (ii) at the offices of the Depositary’s Agents, if any, facilities for the delivery, registration, registration of transfer, surrender, split-up, combination, redemption and conversion of Receipts and deposit and withdrawal of Stock, all in accordance with the provisions of this Deposit Agreement.

The Depositary, acting as transfer agent and Registrar, shall keep books at the Corporate Office for the registration and transfer of Receipts, which books at all reasonable times shall be open for inspection by the record holders of Receipts; provided that any such holder requesting to exercise such right shall certify to the Depositary that such inspection shall be for a proper purpose reasonably related to such person’s interest as an owner of Depositary Shares. The Depositary shall consult with the Company upon receipt of any request for inspection. The Depositary may close such books, at any time or from time to time, when deemed expedient by it in connection with the performance of its duties hereunder.

If the Receipts or the Depositary Shares evidenced thereby or the Stock represented by such Depositary Shares shall be listed on one or more securities exchanges, the Depositary shall, with the approval of the Company, appoint a Registrar for registry of such Receipts or Depositary Shares in accordance with the requirements of such exchange or exchanges. Such Registrar (which may be the Depositary if so permitted by the requirements of such exchange or exchanges) may be removed and a substitute Registrar appointed by the Depositary upon the request or with the approval of the Company. In addition, if the Receipts, such Depositary Shares or such Stock are listed on one or more securities exchanges, the Depositary will, at the request of the Company, arrange such facilities for the delivery, registration, registration of transfer, surrender, split-up, combination, redemption and conversion of such Receipts, such Depositary Shares or such Stock as may be required by law or applicable security exchange regulations.

SECTION 5.2 PREVENTION OR DELAY IN PERFORMANCE BY THE DEPOSITARY, THE DEPOSITARY’S AGENTS, THE REGISTRAR OR THE COMPANY. Neither the Depositary nor any Depositary’s Agent nor the Registrar nor the Company shall incur any liability to any holder of any Receipt, if by reason of any provision of any present or future law or regulation thereunder of the United States of America or of any other governmental authority or of any provision, present or future, of the Certificate of Incorporation or the applicable Certificate of Designation or by reason of any act of god or war or other circumstances beyond the control of the relevant party, the Depositary, any Depositary’s Agent, the Registrar or the Company shall be prevented or forbidden from doing or performing any act or thing that the terms of this Deposit Agreement provide shall be done or performed; nor shall the Depositary, any Depositary’s Agent, the Registrar or the Company incur any liability to any holder of a Receipt (i) by reason of any nonperformance or delay, caused as aforesaid, in the performance of any act or thing that the terms of this Deposit Agreement provide shall or may be done or performed, or (ii) by reason of any exercise of, or failure to exercise, any discretion provided for in this Deposit Agreement except, in the case of the Depositary, any Depositary’s Agent or the Registrar, if any such exercise or failure to exercise discretion is caused by its negligence or willful misconduct.

SECTION 5.3 OBLIGATIONS OF THE DEPOSITARY, THE DEPOSITARY’S AGENTS, THE REGISTRAR AND THE COMPANY. The Company assumes no obligation and shall be subject to no liability under this Deposit Agreement or the Receipts to holders or other persons, except to perform its obligations as are specifically set forth and undertaken by it to perform in this Deposit Agreement without negligence or bad faith. Each of the Depositary, the Depositary’s Agents and the Registrar assumes no obligation and shall be subject to no liability under this Deposit Agreement or the Receipts to holders or other persons, except to perform such obligations as are specifically set forth and undertaken by it to perform in this Deposit Agreement without negligence or willful misconduct.

Neither the Depositary nor any Depositary’s Agent nor the Registrar nor the Company shall be liable for any action or any failure to act by it in reliance upon the advice of or information from legal counsel, accountants, any person presenting Stock for deposit, any holder of a Receipt or any other person believed by it in good faith to be competent to give such advice or information. The Depositary, any Depositary’s Agent, the Registrar and the Company may each rely and shall each be protected in acting upon any written notice, request, direction or other document believed by it to be genuine and to have been signed or presented by the proper party or parties.

The Depositary, the Registrar and any Depositary’s Agent may own and deal in any class of securities of the Company and its affiliates and in Receipts or Depositary Shares. The Depositary may also act as transfer agent or Registrar of any of the securities of the Company and its affiliates.

It is intended that neither the Depositary nor any Depositary’s Agent nor the Registrar shall be deemed to be an “issuer” of the Stock, the Depositary Shares, or the Receipts or other securities issued upon conversion, exchange or redemption of the Stock under the federal securities laws or applicable state securities laws, it being expressly understood and agreed that the Depositary and any Depositary’s Agent and the Registrar are acting only in a ministerial capacity; provided, however, that the Depositary and any Depositary’s Agent agree to comply with all information reporting and withholding requirements applicable to each of them under law or this Deposit Agreement in their capacity as such.

Neither the Depositary (or its officers, directors, employees or agents) nor any Depositary’s Agent nor the Registrar makes any representation or has any responsibility as to the validity of the registration statement pursuant to which the Depositary Shares are registered under the Securities Act, the Stock, the Depositary Shares or any instruments referred to therein or herein, or as to the correctness of any statement made therein or herein; provided, however, that the Depositary is responsible for its representations in this Deposit Agreement.

The Depositary assumes no responsibility for the correctness of the description that appears in the Receipts, which can be taken as a statement of the Company summarizing certain provisions of this Deposit Agreement. Notwithstanding any other provision herein or in the Receipts, the Depositary makes no warranties or representations as to the validity, genuineness or sufficiency of any Stock at any time deposited with the Depositary

hereunder or of the Depositary Shares, as to the validity or sufficiency of this Deposit Agreement, as to the value of the Depositary Shares or as to any right, title or interest of the record holders of Receipts in and to the Depositary Shares except that the Depositary hereby represents and warrants as follows: (i) the Depositary has been duly organized and is validly existing and in good standing under the laws of the State of [ ], with full power, authority and legal right under such law to execute, deliver and carry out the terms of this Deposit Agreement; (ii) this Deposit Agreement has been duly authorized, executed and delivered by the Depositary; and (iii) this Deposit Agreement constitutes, and when executed and delivered, each Receipt will constitute, a valid and binding obligation of the Depositary, enforceable against the Depositary in accordance with its terms, except as enforcement thereof may be limited by bankruptcy, insolvency, reorganization or other similar laws affecting enforcement of creditors’ rights generally and except as enforcement thereof is subject to general principles of equity (regardless of whether enforcement is considered in a proceeding in equity or at law). The Depositary shall not be accountable for the use or application by the Company of its proceeds from the Depositary Shares or the Receipts.

SECTION 5.4 RESIGNATION AND REMOVAL OF THE DEPOSITARY, APPOINTMENT OF SUCCESSOR DEPOSITARY. The Depositary may at any time resign as Depositary hereunder by written notice to the Company of its election to do so, such resignation to take effect upon the appointment of a successor Depositary and its acceptance of such appointment as hereinafter provided.

The Depositary may at any time be removed by the Company by written notice to the Depositary of such removal, such removal to take effect upon the appointment of a successor depositary and its acceptance of such appointment as hereinafter provided.

In case at any time the Depositary acting hereunder shall resign or be removed, the Company shall, within 60 days after the delivery of the notice of resignation or removal, as the case may be, appoint a successor depositary, which shall be a bank or trust company, or an affiliate of a bank or trust company, having its principal office in the United States of America and having a combined capital and surplus of at least $50,000,000. If a successor depositary shall not have been appointed in 60 days, the resigning or removed Depositary may petition a court of competent jurisdiction to appoint a successor depositary. Every successor depositary shall execute and deliver to its predecessor and to the Company an instrument in writing accepting its appointment hereunder, and thereupon such successor depositary, without any further act or deed, shall become fully vested with all the rights, powers, duties and obligations of its predecessor and for all purposes shall be the Depositary under this Deposit Agreement, and such predecessor, upon payment of all sums due it and on the written request of the Company, shall promptly execute and deliver an instrument transferring to such successor all rights and powers of such predecessor hereunder, shall duly assign, transfer and deliver all rights, title and interest in the Stock and any moneys or property held hereunder to such successor and shall deliver to such successor a list of the record holders of all outstanding Receipts. Any successor Depositary shall promptly mail notice of its appointment to the record holders of Receipts.

Any corporation into or with which the Depositary may be merged, consolidated or converted shall be the successor of such Depositary without the execution or filing of any document or any further act. Such successor Depositary may execute the Receipts either in the name of the predecessor Depositary or in the name of the successor Depositary.

SECTION 5.5 CORPORATE NOTICES AND REPORTS. The Company agrees that it will deliver to the Depositary, and the Depositary will, promptly after receipt thereof, transmit to the record holders of Receipts, in each case at the address recorded in the Depositary’s books or the books of any Depositary’s Agent or the Registrar, copies of all notices and reports (including financial statements) required by law, by the rules of any national securities exchange upon which the Stock, the Depositary Shares or the Receipts are listed or by the Certificate of Incorporation or the applicable Certificate of Designation to be furnished by the Company to holders of Stock. Such transmission will be at the Company’s expense and the Company will provide the Depositary with such number of copies of such documents as the Depositary may reasonably request. In addition, the Depositary will transmit to the record holders of Receipts at the Company’s expense such other documents as may be requested by the Company.

SECTION 5.6 DEPOSIT OF STOCK BY THE COMPANY. The Company agrees with the Depositary that neither the Company nor any Company controlled by the Company will at any time deposit any Stock if such Stock is required to be registered under the provisions of the Securities Act and no registration statement is at such time in effect as to such Stock.

SECTION 5.7 INDEMNIFICATION BY THE COMPANY. The Company shall indemnify the Depositary for, and hold it harmless against, any loss, liability, claim or expense (“Loss”) arising out of or in connection with its duties under this Deposit Agreement, including the reasonable costs and expenses of defending itself against Loss, unless such Loss shall have been determined by a court of competent jurisdiction to be a result of the Depositary’s negligence or willful misconduct.

SECTION 5.8 FEES, CHARGES AND EXPENSES. No fees, charges and expenses of the Depositary or any Depositary’s Agent hereunder or of any Registrar shall be payable by any person other than the Company, except for any taxes and other governmental charges and except as provided in this Deposit Agreement. If, at the request of a holder of a Receipt, the Depositary incurs fees, charges or expenses for which it is not otherwise liable hereunder, such holder or other person will be liable for such fees, charges and expenses. All other fees, charges and expenses of the Depositary and any Depositary’s Agent hereunder and of any Registrar (including, in each case, reasonable fees and expenses of counsel) incident to the performance of their respective obligations hereunder will be paid from time to time upon consultation and agreement between the Depositary and the Company as to the amount and nature of such fees, charges and expenses.

ARTICLE VI

AMENDMENT AND TERMINATION

SECTION 6.1 AMENDMENT. The form of the Receipts and any provision of this Deposit Agreement may at any time and from time to time be amended by agreement between the Company and the Depositary in any respect that they may deem necessary or desirable, including to reflect the terms of any Certificate of Designation; provided, however, that no such amendment that shall materially and adversely alter the rights of the holders of Receipts shall be effective as to outstanding Receipts until the expiration of 90 days after notice of such amendment shall have been given to the record holders of outstanding Receipts. Each holder of an outstanding Receipt at the time any such amendment becomes effective shall be deemed, by continuing to hold such Receipt, to consent and agree to such amendment and to be bound by this Deposit Agreement as amended thereby. In no event shall any amendment impair the right, subject to the provisions of this Deposit Agreement, of any holder of any Depositary Shares to surrender the Receipt evidencing such Depositary Shares with instructions to the Depositary to deliver to the holder the Stock or to cause the conversion of such Stock into the Company’s common stock or other securities in accordance with the applicable Certificate of Designation and to deliver all securities, money and other property, if any, represented thereby, except in order to comply with mandatory provisions of applicable law.

SECTION 6.2 TERMINATION. This Deposit Agreement may be terminated by either the Company or the Depositary, upon notice to the other, only if (i) all of the outstanding Depositary Shares have been redeemed or converted for any other securities into which the Stock is convertible, or (ii) there has been a final distribution of the Stock to the holders of Receipts in connection with the Company’s liquidation, dissolution or winding up. The Depositary will mail notice of such termination to the record holders of all Receipts then outstanding at least 30 days prior to the date fixed in such notice for such termination. If any Receipts shall remain outstanding after the date of termination of this Deposit Agreement, the Depositary thereafter shall discontinue the transfer of Receipts, and shall not give any further notices or perform any further acts under this Deposit Agreement, except that the Depositary shall continue to deliver the Stock and any money and other property represented by Receipts, without liability for interest thereon, upon surrender thereof by the holders thereof, and the Depositary shall be discharged from all obligations under this Deposit Agreement except to account for such Stock, money and other property. Upon the termination of this Deposit Agreement, the Company shall be discharged from all obligations under this Deposit Agreement except for its obligations to the Depositary, any Depositary’s Agent and any Registrar under Sections 5.7 and 5.8.

ARTICLE VII

MISCELLANEOUS

SECTION 7.1 COUNTERPARTS. This Deposit Agreement may be executed by the Company and the Depositary in separate counterparts, each of which counterparts, when so executed and delivered, shall be deemed

an original, but all such counterparts taken together shall constitute one and the same instrument. Delivery of an executed counterpart of a signature page to this Deposit Agreement by telecopier shall be effective as delivery of a manually executed counterpart of this Deposit Agreement. Copies of this Deposit Agreement shall be filed with the Depositary and the Depositary’s Agents and shall be open to inspection during business hours at the Corporate Office and the respective offices of the Depositary’s Agents, if any, by any holder of a Receipt.

SECTION 7.2 EXCLUSIVE BENEFITS OF PARTIES. This Deposit Agreement is for the exclusive benefit of the parties hereto, and their respective successors hereunder, and shall not be deemed to give any legal or equitable right, remedy or claim to any other person whatsoever.

SECTION 7.3 INVALIDITY OF PROVISIONS. In case any one or more of the provisions contained in this Deposit Agreement or in the Receipts should be or become invalid, illegal or unenforceable in any respect, the validity, legality and enforceability of the remaining provisions contained herein or therein shall in no way be affected, prejudiced or disturbed thereby.

SECTION 7.4 NOTICES. Any notices to be given to the Company hereunder or under the Receipts shall be in writing and shall be deemed to have been duly given if personally delivered or sent by mail (first class postage prepaid), by a nationally recognized overnight courier service, or by telecopier confirmed by letter, addressed to the Company at ▇▇▇ ▇▇▇▇▇ ▇▇▇▇▇▇, ▇▇▇▇▇ ▇▇▇▇, ▇▇▇ ▇▇▇▇▇▇▇▇▇, ▇▇▇▇▇▇▇▇▇▇ ▇▇▇▇▇, Attention: General Counsel, or at any other place to which the Company may have transferred its principal executive office.

Any notices to be given to the Depositary hereunder or under the Receipts shall be in writing and shall be deemed to have been duly given if personally delivered or sent by mail (first class postage), by a nationally recognized overnight courier service, or by telecopier confirmed by letter, addressed to the Depositary at the Corporate Office.

Except as provided in the next paragraph, any notices given to any record holder of a Receipt hereunder or under the Receipts shall be in writing and shall be deemed to have been duly given if personally delivered or sent by mail (first class postage), by a nationally recognized overnight courier service or by telecopier confirmed by letter, addressed to such record holder at the address of such record holder as it appears on the books of the Depositary or, if such holder shall have filed with the Depositary a written request that notices intended for such holder be mailed to some other address, at the address designated in such request.

In addition, whenever the Certificate of Designation requires any notice to be published, the Depositary will, if requested by the Company, cause such notice to be published in the manner directed by the Company.

Delivery of a notice sent by mail, by overnight courier or by telecopier shall be deemed to be effected at the time when a duly addressed letter containing the same (or a duly addressed letter confirming an earlier notice in the case of a telecopier message) is deposited, postage prepaid, in a post office letter box or with the overnight courier service. The Depositary or the Company may, however, act upon any telecopier message received by it from the other or from any holder of a Receipt, notwithstanding that such telecopier message shall not subsequently be confirmed by letter as aforesaid.

SECTION 7.5 DEPOSITARY’S AGENTS. The Depositary may, with the approval of the Company which approval shall not be unreasonably withheld, from time to time appoint one or more Depositary’s Agents to act in any respect for the Depositary for the purposes of this Deposit Agreement and may vary or terminate the appointment of such Depositary’s Agents.

SECTION 7.6 HOLDERS OF RECEIPTS ARE PARTIES. Notwithstanding that holders of Receipts have not executed and delivered this Deposit Agreement or any counterpart thereof, the holders of Receipts from time to time shall be deemed to be parties to this Deposit Agreement and shall be bound by all of the terms and conditions, and be entitled to all of the benefits, hereof and of the Receipts by acceptance of delivery of Receipts.

SECTION 7.7 GOVERNING LAW. This Deposit Agreement and the Receipts and all rights hereunder and thereunder and provisions hereof and thereof shall be governed by, and construed in accordance with, the law of the State of New York without giving effect to principles of conflict of laws.

SECTION 7.8 HEADINGS. The headings of articles and sections in this Deposit Agreement and in the form of the Receipt set forth in Exhibit A hereto have been inserted for convenience only and are not to be regarded as a part of this Deposit Agreement or to have any bearing upon the meaning or interpretation of any provision contained herein or in the Receipts.

IN WITNESS WHEREOF, Sirna Therapeutics, Inc. and [ ] have duly executed this Deposit Agreement as of the day and year first above set forth and all holders of Receipts shall become parties hereto by and upon acceptance by them of delivery of Receipts issued in accordance with the terms hereof.

Sirna Therapeutics, Inc.

By:

Authorized Officer

, AS DEPOSITARY

By:

Authorized Officer

Exhibit A to Deposit Agreement

[FORM OF DEPOSITARY RECEIPT]

[Unless this certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the Company or its agent for registration of transfer, conversion, exchange or payment, and any certificate issued is registered in the name of Cede & Co. or in such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL in as much as the registered owner hereof, Cede & Co., has an interest herein.]

DEPOSITARY RECEIPT

FOR

DEPOSITARY SHARES

EACH REPRESENTING [ ] OF A SHARE OF

PREFERRED STOCK, SERIES [ ]

Sirna Therapeutics, Inc.

No. CUSIP:

[ ](the “Depositary”) hereby certifies that [Cede & Co.]

[ ]is the registered holder of [ ] Depositary Shares (the “Depositary Shares”), each Depositary Share representing [ ] of a share of [ ] Preferred Stock, Series [ ], $0.01 par value (the “Stock”), of Sirna Therapeutics, Inc., a corporation duly organized and existing under the laws of the State of Delaware (the “Company”), deposited with the Depositary and the same proportionate interest in any and all other property received by the Depositary in respect of such shares of Stock and held by the Depositary under the Deposit Agreement (as defined below). Subject to the terms of the Deposit Agreement, each owner of a Depositary Share is entitled, proportionately, to all the rights, preferences and privileges, and subject to all the limitations and restrictions, of the Stock represented thereby, including any dividend, voting, conversion, redemption, liquidation and sinking fund rights contained in the Certificate of Designation establishing the rights, preferences, privileges, limitations and restrictions of the Stock (the “Certificate of Designation”), copies of which are on file at the office of the Depositary in the City of New York, Borough of Manhattan [ ] at which at any particular time its business in respect of matters governed by the Deposit Agreement shall be administered, which at the time of the execution of the Deposit Agreement is located at [ ] (the “Corporate Office”).

This Depositary Receipt (“Receipt”) shall not be entitled to any benefits under the Deposit Agreement or be valid or obligatory for any purpose unless this Receipt shall have been executed manually or, if a Registrar for the Receipts (other than the Depositary) shall have been appointed, by facsimile by the Depositary by the signature of a duly authorized officer and, if executed by facsimile signature of the Depositary, shall have been countersigned manually by such Registrar by the signature of a duly authorized officer.

THE DEPOSITARY IS NOT RESPONSIBLE FOR THE VALIDITY OF ANY DEPOSITED STOCK. THE DEPOSITARY ASSUMES NO RESPONSIBILITY FOR THE CORRECTNESS OF THE DESCRIPTION SET FORTH IN THIS RECEIPT, WHICH CAN BE TAKEN AS A STATEMENT OF THE COMPANY SUMMARIZING CERTAIN PROVISIONS OF THE DEPOSIT AGREEMENT. UNLESS EXPRESSLY SET FORTH IN THE DEPOSIT AGREEMENT, THE DEPOSITARY MAKES NO WARRANTIES OR REPRESENTATIONS AS TO THE VALIDITY, GENUINENESS OR SUFFICIENCY OF ANY STOCK AT ANY TIME DEPOSITED WITH THE DEPOSITARY UNDER THE DEPOSIT AGREEMENT OR OF THE DEPOSITARY SHARES, AS TO THE VALIDITY OR SUFFICIENCY OF THE DEPOSIT AGREEMENT, AS TO THE VALUE OF THE DEPOSITARY SHARES OR AS TO ANY RIGHT, TITLE OR INTEREST OF THE RECORD HOLDERS OF THE RECEIPTS IN AND TO THE DEPOSITARY SHARES.

The Company will furnish to any holder of this Receipt without charge, upon request addressed to its executive office, a full statement of the designation, relative rights, preferences, privileges, limitations and restrictions of the shares of each authorized class, and of each class of preferred stock authorized to be issued, so far as the same may have been fixed, and a statement of the authority of the board of directors of the Company to designate and fix the relative rights, preferences, privileges, limitations and restrictions of other classes.

This Receipt is continued on the reverse hereof and the additional provisions therein set forth for all purposes have the same effect as if set forth at this place.

Dated:

as Depositary and Registrar

By:

Authorized Officer

Further Conditions and Agreements Forming Part of this Receipt Appear on the Reverse Side.

[REVERSE OF DEPOSITARY RECEIPT]

1. THE DEPOSIT AGREEMENT. Receipts, of which this Receipt is one, are made available upon the terms and conditions set forth in the Deposit Agreement, dated as of [ ] (the “Deposit Agreement”), among the Company, the Depositary and all holders from time to time of Receipts. The Deposit Agreement (copies of which are on file at the Corporate Office and at the office of any agent of the Depositary) sets forth the rights of holders of Receipts and the rights and duties of the Depositary. The statements made on the face and the reverse of this Receipt are summaries of certain provisions of the Deposit Agreement and are subject to the detailed provisions thereof, to which reference is hereby made. In the event of any conflict between the provisions of this Receipt and the provisions of the Deposit Agreement, the provisions of the Deposit Agreement will govern.

2. DEFINITIONS. Unless otherwise expressly herein provided, all defined terms used herein shall have the meanings ascribed thereto in the Deposit Agreement.

3. REDEMPTION BY THE COMPANY; REPURCHASE BY THE COMPANY. Whenever the Company shall redeem shares of Stock in accordance with a Certificate of Designation, it shall (unless otherwise agreed in writing with the Depositary) give the Depositary in its capacity as Depositary not less than 3 business days’ prior notice of the proposed date of the mailing of a notice of redemption of Stock and the simultaneous redemption of the Depositary Shares representing the Stock to be redeemed and of the number of such shares of Stock held by the Depositary to be redeemed. Unless the Certificate of Designation for a specific series of Stock provides for a different notice period with respect to that Stock in the event of its redemption, the Depositary shall, as directed by the Company in writing, mail, first class postage prepaid, notice of the redemption not less than 30 and not more than 60 days prior to the date fixed for redemption of such Stock and Depositary Shares, to the record holders of the Receipts evidencing the Depositary Shares to be so redeemed, at the addresses of such holders as the same appear on the records of the Depositary or any Depositary’s Agent or Registrar. Notwithstanding the foregoing, neither failure to mail or publish any such notice to one or more such holders nor any defect in any notice shall affect the sufficiency of the proceedings for redemption. On the date of any such redemption, the Depositary shall surrender the certificate or certificates held by the Depositary evidencing the number of shares of Stock to be redeemed in the manner specified in the notice of redemption. The Depositary shall, thereafter, redeem the number of Depositary Shares representing such redeemed Stock upon the surrender of Receipts evidencing such Depositary Shares in the manner provided in the notice sent to record holders of Receipts. Notice having been mailed as aforesaid, from and after the redemption date (unless the Company shall have failed to redeem the shares of Stock to be redeemed by it upon the surrender of the certificate or certificates therefore by the Depositary as described above), the Depositary Shares called for redemption shall be deemed no longer to be outstanding and all rights of the holders of Receipts evidencing such Depositary Shares (except the right to receive the cash, securities or other property payable upon redemption upon surrender of such Receipts) shall, to the extent of such Depositary Shares, cease and terminate. The foregoing shall be subject further to the terms and conditions of the applicable Certificate of Designation.

Whenever the Company shall be required to make an offer to repurchase Depositary Shares in accordance with a Certificate of Designation, it shall (unless otherwise agreed in writing with the Depositary) give the Depositary in its capacity as Depositary not less than 3 business days’ prior notice of the required date of the mailing of a notice of the repurchase offer. The Depositary shall, as directed by the Company in writing, mail, first class postage prepaid, notice of the relevant terms of the repurchase offer, as provided by the Company, to the record holders of the Receipts at the addresses of such holders as the same appear on the records of the Depositary or any Depositary’s Agent or Registrar. The Depositary shall, thereafter, receive from each holder electing to have Depositary Shares repurchased pursuant to the repurchase offer in accordance with the instructions in the notice, the holder’s Receipts, with an appropriate form duly completed prior to the repurchase date. In case the aggregate number of Depositary Shares offered for repurchase by the holders exceeds the amount of Depositary Shares which the Company has offered to repurchase pursuant to the repurchase offer, the Depositary Shares to be repurchased shall be selected by the Depositary by lot or proportionately, as may be determined by the Depositary. The foregoing is subject further to the terms and conditions of the applicable Certificate of Designation.

4. CONVERSION. In the event that the Stock, in accordance with its Certificate of Designation, is convertible into the Company’s common stock or other securities, subject to the terms and conditions of the Deposit Agreement, a holder of a Receipt or Receipts may surrender such Receipt or Receipts at the Corporate Office or at such other office or to a Depositary’s Agent that the Depositary may designate for such purpose, together with a notice of

conversion duly completed and executed, thereby directing the Depositary or such Depositary’s Agent to instruct the Company to cause the conversion of the number of shares of Stock specified in such notice of conversion into shares of the Company’s common stock or other securities at the rate specified in the applicable Certificate of Designation, and an assignment of such Receipt or Receipts to the Company or in blank, duly completed and executed, along with any other documents or instruments and any amounts required by the applicable Certificate of Designation.

Upon receipt by the Depositary or a Depositary’s Agent of a Receipt or Receipts of such notice, assignment and other documents, instruments or amounts, the Depositary or such Depositary’s Agent shall instruct the Company, subject to any adjustment provided for in the applicable Certificate of Designation, (i) to cause the conversion at the rate specified in the applicable Certificate of Designation of the number of shares of Stock evidenced by the Receipt or Receipts so surrendered for conversion as specified in the written notice to the Depositary or such Depositary’s Agent and (ii) to cause the delivery to the holder of such Receipt or Receipts of (a) a certificate or certificates evidencing the number of whole shares of the Company’s common stock or other securities into which such Stock has been converted, and (b) the amount of cash or other property, if any, to which such holder is entitled in lieu of fractional shares of, or fractional interests in, the Company’s common stock or other securities otherwise deliverable by the Company upon such conversion, calculated in accordance with the applicable Certificate of Designation. Upon such conversion, the Depositary or such Depositary’s Agent (i) shall deliver to the holder a Receipt evidencing the number of Depositary Shares evidenced by the surrendered Receipt or Receipts in excess of the number of Depositary Shares evidenced by such Receipt or Receipts that have been so converted, (ii) shall cancel the Receipts surrendered for conversion and (iii) shall deliver to the Company for cancellation the number of shares of Stock evidenced by the Receipts so surrendered and so converted.

No fractional shares or other fractional interests in the Company’s common stock or other securities shall be deliverable by the Company upon conversion of the Stock represented by the Depositary Shares.

5. WITHDRAWAL OF STOCK. Holders of Receipts shall have the right, upon payment of any amount due to the Depositary with respect to the Receipts, to withdraw any or all of the Stock (but only in whole shares of Stock) represented by the Depositary Shares and all money and other property, if any, represented by such Depositary Shares by surrendering the Receipt or Receipts evidencing such Depositary Shares at the Corporate Office, or at such other offices as the Depositary may designate for such withdrawal (and cancellation of the surrendered Receipts as provided in the Deposit Agreement).

6. TRANSFERS, SPLIT-UPS, COMBINATIONS. Subject to Paragraphs 7, 8 and 9 below, this Receipt is transferable on the books of the Depositary upon surrender of this Receipt to the Depositary at the Corporate Office or at such other offices as the Depositary may designate for such purchase, properly endorsed or accompanied by a properly executed instrument of transfer, together with evidence of the payment of any transfer taxes as may be required by law, and upon such transfer the Depositary shall execute and deliver a Receipt or Receipts to or upon the order of the person entitled thereto, all as provided in and subject to the Deposit Agreement. Subject to the Deposit Agreement, this Receipt may be split into other Receipts or combined with other Receipts into one Receipt evidencing the same aggregate number of Depositary Shares evidenced by the Receipt or Receipts surrendered; provided, however, that the Depositary shall not issue any Receipt evidencing a fractional Depositary Share.

7. CONDITIONS TO SIGNING AND DELIVERY, TRANSFER, ETC., OF RECEIPTS.

Prior to the execution and delivery, registration of transfer, split-up, combination, or surrender of this Receipt, the delivery of any distribution hereon or withdrawal or deposit of the Stock evidenced hereby, or the exercise of any

applicable conversion right, the Depositary, any of the Depositary’s Agents, the Registrar or the Company may require any or all of the following:

(i) payment to it of a sum sufficient for the payment (or, in the event that the Depositary or the Company shall have made such payment, the reimbursement to it) of any tax or other governmental charge or fee with respect thereto (including any such tax or charge or fee with respect to Stock being deposited or withdrawn or with respect to other property of the Company being issued upon redemption or conversion); (ii) production of proof satisfactory to it as to the identity and genuineness of any signature; and (iii) compliance with such reasonable regulations, if any, as the Depositary or the Company may establish not inconsistent with the Deposit Agreement. Any person presenting Stock for deposit, or any holder of this Receipt, may be required to file such proof of residence or other information, to execute such certificates and to make such representations and warranties as the Depositary or the Company may reasonably deem necessary or proper. The Depositary or the Company may withhold or delay the delivery of this Receipt, the registration of transfer or redemption of this Receipt, the withdrawal of the Stock represented by the Depositary Shares evidenced by this Receipt, the distribution of any dividend or other distribution or the exercise of any applicable conversion right, until such proof or other information is filed, such certificates are executed or such representations and warranties are made.

8. SUSPENSION OF DELIVERY, TRANSFER, ETC. The registration of transfer, split-up, combination or surrender of this Receipt and the withdrawal of deposited Stock or the exercise of any applicable conversion right may be suspended (i) during any period when the register of stockholders of the Company is closed, (ii) if any such action is deemed necessary or advisable by the Depositary, any of the Depositary’s Agents or the Company at any time or from time to time because of any requirement of law or of any government or governmental body or commission, or under any provision of the Deposit Agreement, or (iii) with the approval of the Company, for any other reason.

9. PAYMENT OF TAXES OR OTHER GOVERNMENTAL CHARGES. If any tax or other governmental charge or fee shall become payable by or on behalf of the Depositary with respect to (i) this Receipt, (ii) the Depositary Shares evidenced by this Receipt, (iii) the Stock (or fractional interest therein) or other property represented by such Depositary Shares, or (iv) any transaction referred to in Section 4.6 of the Deposit Agreement, such tax (including transfer, issuance or acquisition taxes, if any) or governmental charge or fee shall be payable by the holder of this Receipt, who shall pay the amount thereof to the Depositary. Until such payment is made, registration or transfer of this Receipt or any split-up or combination of this Receipt or any withdrawal of the Stock or money or other property, if any, represented by the Depositary Shares evidenced by this Receipt upon its surrender or the exercise of any applicable conversion right may be refused, any dividend or other distribution may be withheld and any part or all of the Stock or other property represented by the Depositary Shares evidenced by this Receipt may be sold for the account of the holder hereof (after attempting by reasonable means to notify such holder prior to such sale). Any dividend or other distribution so withheld and the proceeds of any such sale may be applied to any payment of such tax or other governmental charge or fee, the holder of this Receipt remaining liable for any deficiency.

10. AMENDMENT. The form of the Receipts and any provision of the Deposit Agreement may at any time and from time to time be amended by agreement between the Company and the Depositary in any respect that they may deem necessary or desirable, including to reflect the terms of any Certificate of Designation; provided, however, that no such amendment that shall materially and adversely alter the rights of the holders of Receipts shall be effective as to outstanding Receipts until the expiration of 90 days after notice of such amendment shall have been given to the record holders of outstanding Receipts. Each holder of an outstanding Receipt at the time any such amendment becomes effective shall be deemed, by continuing to hold such Receipt, to consent and agree to such amendment and to be bound by the Deposit Agreement as amended thereby. In no event shall any amendment impair the right, subject to the provisions of the Deposit Agreement, of the holder of the Depositary Shares evidenced by this Receipt to surrender this Receipt with instructions to the Depositary to deliver to the holder the Stock or to cause the conversion of such Stock into the Company’s common stock or other securities in accordance with the applicable Certificate of Designation and to deliver all securities, money and other property, if any, represented thereby, except in order to comply with mandatory provisions of applicable law.

11. FEES, CHARGES AND EXPENSES. The Company will pay all fees, charges and expenses of the Depositary, except for taxes and other governmental charges and such charges as are otherwise expressly provided for in the Deposit Agreement.

12. TITLE TO RECEIPTS. It is a condition of this Receipt, and every successive holder hereof by accepting or holding the same consents and agrees, that title to this Receipt (and to the Depositary Shares evidenced hereby), when properly endorsed or accompanied by a properly executed instrument of transfer, is transferable by delivery with the same effect as in the case of investment securities in general; provided, however, that the Depositary may, notwithstanding any notice to the contrary, treat the record holder hereof at such time as the absolute owner hereof for the purpose of determining the person entitled to distribution of dividends or other distributions or to any notice provided for in the Deposit Agreement and for all other purposes.

13. DIVIDENDS AND DISTRIBUTIONS. Whenever the Depositary shall receive any cash dividend or other cash distribution on the Stock (other than cash dividends or cash distributions paid by the Company in lieu of fractional shares or other fractional interests in the Company’s common stock or other securities otherwise deliverable by the Company in accordance with the applicable Certificate of Designation), the Depositary shall, subject to the provisions of the Deposit Agreement, distribute to record holders of Receipts on the record date fixed pursuant to paragraph 15 such amounts of such sums as are, as nearly as practicable, in proportion to the respective numbers of Depositary Shares evidenced by the Receipts held by such holders; provided, however, that in case the Company or the Depositary shall be required by law to withhold and does withhold from any cash dividend or other cash distribution in respect of the Stock an amount on account of taxes, the amount made available for distribution or distributed in respect of Depositary Shares shall be reduced accordingly. The Depositary shall distribute or make available for distribution, as the case may be, only such amount, however, as can be distributed without attributing to any holder of Depositary Shares a fraction of one cent and any balance not so distributable shall be held by the Depositary (without liability for interest thereon) and shall be added to and be treated as part of the next sum received by the Depositary for distribution to record holders of Receipts then outstanding.

14. SUBSCRIPTION RIGHTS, PREFERENCES OR PRIVILEGES. If the Company shall at any time offer or cause to be offered to the persons in whose name Stock is registered on the books of the Company any rights, preferences or privileges to subscribe for or to purchase any securities or any rights, preferences or privileges of any other nature, such rights, preferences or privileges shall in each such instance, subject to the provisions of the Deposit Agreement, be made available by the Depositary to the record holders of Receipts in such manner as the Company shall instruct.

15. NOTICE OF DIVIDENDS, FIXING OF RECORD DATE. Whenever (i) any cash dividend or other cash distribution shall become payable, or any distribution other than cash shall be made, or any rights, preferences or privileges shall at any time be offered, with respect to the Stock, or (ii) the Depositary shall receive notice of any meeting at which holders of Stock are entitled to vote or of which holders of Stock are entitled to notice, or (iii) of any mandatory conversion of, or any election on the part of the Company to call for redemption or exchange of, any shares of Stock, in accordance with the applicable Certificate of Designation or otherwise, the Depositary shall in each such instance fix a record date (which shall be the same date as the record date fixed by the Company with respect to the Stock) for the determination of the holders of Receipts (x) who shall be entitled to receive such dividend, distribution, rights, preferences or privileges or the net proceeds of the sale thereof, or (y) who shall be entitled to give instructions for the exercise of voting rights at any such meeting or to receive notice of such meeting or of such conversion, exchange or redemption.

16. VOTING RIGHTS. Upon receipt of notice of any meeting at which the holders of Stock are entitled to vote, the Depositary shall, as soon as practicable thereafter, mail to the record holders of Receipts a notice, which shall contain (i) such information as is contained in such notice of meeting, (ii) a statement that the holders of Receipts at the close of business on a specified record date determined as provided in paragraph 15 will be entitled, subject to any applicable provision of law, the Certificate of Incorporation or the applicable Certificate of Designation, to instruct the Depositary as to the exercise of the voting rights pertaining to the Stock represented by their respective Depositary Shares, and (iii) a brief statement as to the manner in which such instructions may be given. Upon the written request of a holder of this Receipt on such record date, the Depositary shall endeavor insofar as practicable to vote or cause to be voted the Stock represented by the Depositary Shares evidenced by this Receipt in accordance with the instructions set forth in such request. The Company hereby agrees to take all reasonable action that may be deemed necessary by the Depositary in order to enable the Depositary to vote such Stock or cause such Stock to be voted. In the absence of specific instructions from the holder of this Receipt, the Depositary will abstain from voting to the extent of the Stock represented by the Depositary Shares evidenced by this Receipt.

17. REPORTS, INSPECTION OF TRANSFER BOOKS. The Company agrees that it will deliver to the Depositary, and the Depositary will, promptly after receipt thereof, transmit to the record holders of Receipts, in each case at the address recorded in the Depositary’s books or the books of any Depositary’s Agent or the Registrar, copies of all notices and reports (including financial statements) required by law, by the rules of any national securities exchange upon which the Stock, the Depositary Shares or the Receipts are listed or by the Certificate of Incorporation or the applicable Certificate of Designation to be furnished by the Company to holders of Stock. The Depositary, acting as transfer agent and Registrar, shall keep books at the Corporate Office for the registration and transfer of Receipts, which books at all reasonable times shall be open for inspection by the record holders of Receipts; provided that any such holder requesting to exercise such right shall certify to the Depositary that such inspection shall be for a proper purpose reasonably related to such person’s interest as an owner of Depositary Shares.

18. LIABILITY OF THE DEPOSITARY, THE DEPOSITARY’S AGENTS, THE REGISTRAR AND THE COMPANY. Neither the Depositary nor any Depositary’s Agent nor the Registrar nor the Company shall incur any liability to any holder of this Receipt, if by reason of any provision of any present or future law or regulation thereunder of any governmental authority or of any provision, present or future, of the Certificate of Incorporation or the applicable Certificate of Designation or by reason of any act of god or war or other circumstances beyond the control of the relevant party, the Depositary, any Depositary’s Agent, the Registrar or the Company shall be prevented or forbidden from doing or performing any act or thing that the terms of the Deposit Agreement provide shall be done or performed; nor shall the Depositary, any Depositary’s Agent, the Registrar or the Company incur any liability to any holder of this Receipt (i) by reason of any nonperformance or delay, caused as aforesaid, in the performance of any act or thing that the terms of the Deposit Agreement provide shall or may be done or performed or (ii) by reason of any exercise of, or failure to exercise, any discretion provided for in the Deposit Agreement except, in the case of the Depositary, any Depositary’s Agent or the Registrar, if such exercise or failure to exercise discretion is caused by its negligence or willful misconduct.

19. OBLIGATIONS OF THE DEPOSITARY, THE DEPOSITARY’S AGENT, THE REGISTRAR AND THE COMPANY. The Company assumes no obligation and shall be subject to no liability under the Deposit Agreement or this Receipt to the holder hereof or other persons, except to perform its obligations as are specifically set forth and undertaken by it to perform in the Deposit Agreement without negligence or bad faith. Each of the Depositary, the Depositary’s Agents and the Registrar assumes no obligation and shall be subject to no liability under the Deposit Agreement or this Receipt to the holder hereof or other persons, except to perform such obligations as are specifically set forth and undertaken by it to perform in the Deposit Agreement without negligence or willful misconduct.

Neither the Depositary nor any Depositary’s Agent nor the Registrar nor the Company shall be liable for any action or failure to act by it in reliance upon the advice of or information from legal counsel, accountants, any person presenting Stock for deposit, any holder of this Receipt or any other person believed by it in good faith to be competent to give such advice or information.

20. TERMINATION OF DEPOSIT AGREEMENT. The Deposit Agreement may be terminated only if (i) all of the outstanding Depositary Shares have been redeemed or converted for any other securities into which the Stock is convertible or (ii) there has been a final distribution of the Stock to the holders of Receipts in connection with the Company’s liquidation, dissolution or winding up. The Depositary will mail notice of such termination to the record holders of all Receipts then outstanding at least 30 days prior to the date fixed in such notice for such termination. Upon the termination of the Deposit Agreement, the Company shall be discharged from all obligations thereunder except for its obligations to the Depositary, any Depositary’s Agent and any Registrar under Sections 5.7 and 5.8 of the Deposit Agreement.

If any Receipts remain outstanding after the date of termination of the Deposit Agreement, the Depositary thereafter shall discontinue all functions and be discharged from all obligations as provided in the Deposit Agreement, except as specifically provided therein.

21. GOVERNING LAW. The Deposit Agreement and this Receipt and all rights thereunder and hereunder and provisions thereof and hereof shall be governed by, and construed in accordance with, the law of the State of New York without giving effect to principles of conflict of laws.

FORM OF ASSIGNMENT

FOR VALUE RECEIVED, the undersigned hereby sells, assigns and transfers unto the within Receipt and all rights and interests represented by the Depositary Shares evidenced thereby, and hereby irrevocably constitutes and appoints [ ] attorney, to transfer the same on the books of the within-named Depositary, with full power of substitution in the premises.

Dated: Signature:

NOTE: The signature to this assignment

must correspond with the name as written

upon the face of the Receipt in every

particular, without alteration or

enlargement, or any change whatever.

SIRNA THERAPEUTICS, INC. Issuer and

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