X0202 4 2008-05-07 0001068796 MAXYGEN INC MAXY 0001180764 HOWARD RUSSELL J C/O MAXYGEN, INC. 515 GALVESTON DRIVE REDWOOD CITY CA 94063 1 1 0 0 Chief Executive Officer Common Stock 2008-05-07 4 A 0 125000 0 A 131683 D Common Stock 448229 I Trust Common Stock 5924 I Held by Maxygen, Inc. 401(k) plan Restricted stock units granted under the Maxygen, Inc. 2006 Equity Incentive Plan. Each restricted stock unit is payable solely by delivery of an equal number of shares of Maxygen, Inc. common stock and vests as to 1/4 of the underlying shares on May 1, 2009 and vests as to the remaining underlying shares on May 3, 2010. Restricted stock unit awards include the ability to have shares withheld to satisfy income tax obligations. Russell J. Howard and Maureen C. Howard Trust John Borkholder - Attorney-in-fact 2008-05-09