Exhibit 4.1

[FACE OF CERTIFICATE]

Number

[LOGO]

TAPESTRY Pharmaceuticals

TAPESTRY PHARMACEUTICALS, INC.

INCORPORATED UNDER THE LAWS OF THE STATE OF DELAWARE

COMMON STOCK

Shares

CUSIP 876031 20 4

SEE REVERSE FOR CERTAIN DEFINITIONS

THIS IS TO CERTIFY that

is the owner of

fully paid and non-assessable shares of Common Stock of the par value of seventy-five hundredths of One Cent ($.0075) each of

Tapestry Pharmaceuticals, Inc.

transferable on the books of the Corporation by holder hereof in person or by duly authorized attorney upon the surrender of this Certificate properly endorsed. This Certificate is not valid until countersigned by the Transfer Agent and Registrar.

WITNESS the facsimile seal of the Corporation and the facsimile signatures of its duly authorized officers.

Dated:

/s/

SECRETARY

[SEAL]

/s/

CHAIRMAN

COUNTERSIGNED AND REGISTERED:

AMERICAN STOCK TRANSFER & TRUST COMPANY

(New York, N.Y.)

TRANSFER AGENT AND REGISTRAR

BY

AUTHORIZED SIGNATURE

[REVERSE OF CERTIFICATE]

TAPESTRY PHARMACEUTICALS, INC.

The Corporation will furnish without charge to any stockholder who so requests a full statement of, and the authority of the Board of Directors to fix, the designation, relative rights, preferences and limitations of the shares of each class of stock, or series thereof, authorized to be issued.

The following abbreviations, when used in the inscription on the face of this certificate, shall be construed as though they were written out in full according to applicable laws or regulations:

TEN COM - as tenants in common

TEN ENT - as tenants by the entireties

JT TEN - as joint tenants with right of survivorship and not as tenants in common

Additional abbreviations may also be used though not in the above list.

For Value Received,            hereby sell, assign and transfer unto

PLEASE INSERT SOCIAL SECURITY OR OTHER IDENTIFYING NUMBER OF ASSIGNEE

(PLEASE PRINT OR TYPEWRITE NAME AND ADDRESS, INCLUDING ZIP CODE, OF ASSIGNEE)

shares of the capital stock represented by the within Certificate, and do hereby irrevocably constitute and appoint

Attorney to transfer the said stock on the books of the within named Corporation with full power of substitution in the premises.

Dated

NOTICE: THE SIGNATURE(S) TO THIS ASSIGNMENT MUST CORRESPOND WITH THE NAME(S) AS WRITTEN UPON THE FACE OF THE CERTIFICATE IN EVERY PARTICULAR, WITHOUT ALTERATION OR ENLARGEMENT OR ANY CHANGE WHATEVER.