APAF1 and cancer: Cancer cell death induced by anticancer drug is caused by intrinsic or extrinsic apoptosis signaling pathways including Bcl-2/Bax/Bid/cytochrome C (cyto C)/apoptotic protease activating factor-1 (Apaf-1)/caspase-9 or death receptors (DR)/caspase-8/Bid together with executional activity of caspase-3 and caspase-7 [11,12].