Exhibit 10.25

AMENDMENT NO. 1 TO LICENSE AGREEMENT

This Amendment No. 1, effective February 28, 2006, to the License Agreement effective upon the Effective Time (the “Agreement”), by and between Dana-Farber Cancer Institute, Inc., and FibroGen, Inc. and its subsidiaries (collectively, the “Parties”). The Parties, for good and valuable consideration, the receipt and sufficiency of which is hereby acknowledged, agree as follows:

(1) Article 22 is replaced in it’s entirety with the following:

“The terms contained in this Agreement shall be null and void if the certificate of merger with the Secretary of State of the State of Delaware for the Imigen Acquisition is not filed on or before March 15, 2006.”; and

(2) Except as otherwise provided herein, the Agreement has not been modified or amended and remains in full force and effect.

IN WITNESS WHEREOF, the Parties have executed this Amendment No. 1 to License Agreement as of the effective date set forth above.

FIBROGEN, INC.		DANA FARBER CANCER INSTITUTE, INC.
By:	/s/ Thomas B. Neff	By:	/s/ Anthony del Campo
Name:	T.B. Neff	Name:	Anthony A. del Campo, M.B.A.
Title:	CEO	Title:	Vice President, Research and Technology Ventures, Dana Farber Cancer Institute
Date:	28 Feb 2006	Date:	2/28/2006

Confidential