JOINT FILING AGREEMENT
The undersigned hereby agree that the statement on Schedule 13G with
respect to the shares of common stock of Threshold Pharmaceuticals, Inc. is, and
any amendment thereto (collectively, the "Schedule 13G") signed by each of the
undersigned shall be, filed on behalf of each of the undersigned pursuant to and
in accordance with the provisions of Rule 13d-1(k) promulgated under the
Securities Exchange Act of 1934, as amended. The undersigned hereby further
agree that this Joint Filing Agreement be included as an exhibit to such
statement and any such amendment. This Joint Filing Agreement may be executed in
any number of counterparts, all of which taken together shall constitute one and
the same instrument.
Dated: February 10, 2006
/S/ XXXXXXXX XXXXXXXXX
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Xxxxxxxx XxXxxxxxx, as a member of ProQuest
Associates II LLC and on behalf of ProQuest
Investments II, L.P. and ProQuest
Investments II Advisors Fund, L.P.
*
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Xxx Xxxxxx, individually
*
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Xxxxx Xxxxxxxxx, individually
*By: /S/ XXXXXXXX XXXXXXXXX
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Xxxxxxxx XxXxxxxxx, Attorney-in-Fact
Power of Attorney filed as an exhibit to the Schedule 13G
