CASP9 and gastric cancer: In the western blot assays, PF-induced apoptosis via caspase-9 and caspase-3 cleavage and Z-VAD-FMK blocked the inhibition of cell viability, the induction of LDH and caspase-3 activity, and caspase-3 cleavage in PF-treated AGS and SNU-638 gastric cancer cells.