To determine whether the anti-cancer effects of OA were associated with apoptosis, we quantified apoptosis in DU145, MCF-7, and U87 cells with Annexin V-FITC staining using cells either individually treated with OA, PD98059, or LY294002, or in a combination of OA and PD98059 or OA and LY294002. This evidence concerns the gene ANXA5 and cancer.