THRESHOLD PHARMACEUTICALS, INC.
      POWER OF ATTORNEY

     Know all by these presents, that the undersigned hereby constitutes
and appoints each of Harold E. Selick, Kenneth B. Stratton and Cathy Davis signing singly,
the undersigned's true and lawful attorney-in-fact to:

(1) execute for and on behalf of the undersigned, in the undersigned's
capacity as an officer and/or director of Threshold Pharmaceuticals, Inc.,
a Delaware corporation (the "Company"), Forms 3, 4, and 5 in accordance
with Section 16(a) of the Securities Exchange Act of 1934 and the rules thereunder;

(2) do and perform any and all acts for and on behalf of the
undersigned which may be necessary or desirable to complete and execute any
such Form 3, 4, or 5, complete and execute any amendment or amendments
thereto, and timely file such form with the United States Securities
and Exchange Commission and any stock exchange or similar authority; and

(3) take any other action of any type whatsoever in connection with the
foregoing which, in the opinion of such attorney-in-fact, may be of
benefit to, in the best interest of, or legally required by, the undersigned,
it being understood that the documents executed by such attorney-in-fact
on behalf of the undersigned pursuant to this Power of Attorney shall be
in such form and shall contain such terms and conditions as such attorney-in-fact
may approve in such attorney-in-fact's discretion.

     The undersigned hereby grants to each such attorney-in-fact
full power and authority to do and perform any and every act and
thing whatsoever requisite, necessary, or proper to be done in the
exercise of any of the rights and powers herein granted, as fully
to all intents and purposes as the undersigned might or could do if
personally present, with full power of substitution or
revocation, hereby ratifying and confirming all that such
attorney-in-fact, or such attorney-in-fact's substitute or
substitutes, shall lawfully do or cause to be done by virtue of this Power
of Attorney and the rights and powers herein granted.
The undersigned acknowledges that the foregoing attorneys-in-fact,
in serving in such capacity at the request of the undersigned,
are not assuming, nor is the Company assuming, any of the
undersigned's responsibilities to comply with Section 16 of the
Securities Exchange Act of 1934.

     This Power of Attorney shall remain in full force and effect until
the undersigned is no longer required to file Forms 3, 4, and 5
with respect to the undersigned's holdings of and transactions in
securities issued by the Company, unless earlier revoked by the
undersigned in a signed writing delivered to the foregoing attorneys-in-fact.

     IN WITNESS WHEREOF, the undersigned has caused this Power of
Attorney to be executed as of this 1st day of November 2006.

      /s/ Michael Brawer
      Signature
      Michael Brawer
      Print Name