X0201 4/A 2003-10-01 2003-10-03 0 0000820237 GEN PROBE INC GPRO 0001265721 ARNOLD LYLE J GEN-PROBE INCORPORATED 10210 GENETIC CENTER DRIVE SAN DIEGO CA 92121 0 1 0 0 VP, Research Employee Stock Option (Right to Buy) 27.08 2003-10-01 4 A 0 20000 0 A 2013-10-01 Common Stock 20000 20000 D This amendment is being filed to correct the transaction date and to correct the number of shares subject to the stock option, which was erroneously reported on the reporting person's Form 4 filed October 3, 2003 as 10,000 shares. Option vests as follows: 25% vest on 10/1/04; 1/48th vesting monthly following three years. /s/ R. William Bowen, Attorney-in-Fact 2003-12-03