EXHIBIT 4.3 FORM OF 2007 D WARRANT AMENDMENT AMENDMENT NO. 1 TO COMMON STOCK PURCHASE WARRANT D This AMENDMENT NO. 1 TO COMMON STOCK PURCHASE WARRANT D dated as of December 20, 2007 (this "Amendment"), among Geron Corporation, a Delaware corporation...Common Stock Purchase Warrant Amendment • December 21st, 2007 • Geron Corp • Pharmaceutical preparations
