XIAP and cancer: Now it is clear that TNFα determines the fate of cancers based on cancer expression of inhibitor of apoptosis proteins (IAPs) family of E3 ubiquitin ligases, including cIAP1 (BIRC2), cIAP2 (BIRC3), X-IAP (BIRC4), etc. IAP proteins, which are frequently overexpressed in human tumors and promote cancer cell survival [13], induce proteasomal degradation of caspases to block apoptosis [14, 15].