FAS and cancer: Since extrinsic apoptosis of cancer cells is initiated by binding of death receptors and their ligands, the death receptors may function as signaling gateway in which Fas/CD95 ligands (FasL/CD95L) and some cytokines such as TNFα and TNF superfamily member 10 (TNFSF10, also known as TRAIL) play great roles in inducing apoptosis.