Abstract: Tumour necrosis factor(TNF)-related apoptosis-inducing ligand(TRAIL) is a member of the TNF superfamily which selectively induces apoptosis in a broad range of cancer cell lines, but not in many normal cells. TRAIL induces apoptosis by activating Caspases and the mitochondrial-dependent apoptotic pathway. Cell death induced by TRAIL can be blocked by a dominant-negative TRAIL receptor, decoy receptors(DcR), and is regulated by members of the Bcl-2 family of proteins. This review is focused on the apoptotic signaling pathways regulated by TRAIL and summarizes what is known about their clinical role.