Tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL), also referred to as Apo2 ligand, first identified based on its sequence homology to TNF and Fas/Apo ligand is a member of the TNF family of cytokines and either exists as a type II membrane or soluble protein. The morphological and cellular changes caused by the introduction of soluble TRAIL to Jurkat cells are indistinguishable from those caused by the introduction of soluble FAS-L. Osteoprotegerin (OPG) has also been identified as receptor capable of inhibiting TRAIL-induced apoptosis. The selectivity of soluble TRAIL at triggering apoptosis in transformed cells as compared to normal cells has led to its investigation as a potential cancer therapeutic.
