X0202 4 2007-09-18 0001068796 MAXYGEN INC MAXY 0001101713 RINGOLD GORDON C/O MAXYGEN, INC. 515 GALVESTON DRIVE REDWOOD CITY CA 94063 1 0 0 0 Common Stock 2007-09-18 4 S 0 100 8.57 D 289896 I Trust Common Stock 2007-09-18 4 S 0 200 8.50 D 289696 I Trust Common Stock 2007-09-18 4 S 0 100 8.35 D 289596 I Trust Common Stock 2007-09-18 4 S 0 2000 8.00 D 287596 I Trust Common Stock 2007-09-18 4 S 0 100 7.97 D 287496 I Trust Common Stock 2007-09-18 4 S 0 100 7.88 D 287396 I Trust Common Stock 2007-09-18 4 S 0 100 7.87 D 287296 I Trust Common Stock 2007-09-18 4 S 0 100 7.86 D 287196 I Trust Common Stock 2007-09-18 4 S 0 200 7.85 D 286996 I Trust Common Stock 2007-09-18 4 S 0 200 7.84 D 286796 I Trust Common Stock 2007-09-18 4 S 0 200 7.83 D 286596 I Trust Common Stock 2007-09-18 4 S 0 100 7.81 D 286496 I Trust Common Stock 63198 I By Technogen The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on August 16, 2007. Gordon Ringold and Tanya Zarucki 1999 Trust The amount of securities reported consists of shares of Maxygen common stock held by Technogen Enterprises, L.L.C. Dr. Ringold is a Managing Member of Technogen Enterprises, L.L.C. and has shared power to vote or direct the vote of and shared power to dispose or direct the disposition of the shares held by the limited liability company. Dr. Ringold disclaims beneficial ownership of these shares except to the extent of his pecuniary interest in the limited liability company. John Borkholder - Attorney-in-fact 2007-09-19