Tumor necrosis factor-related apoptosis-inducing ligand (Trail) is one of the several members of the tumor necrosis factor TNF gene superfamily that induce apoptosis through engagement of death receptors (DRs). By interacting with two receptors, named DR4 (death receptor 4 or TRAIL-R1) and DR5 (TRAIL-R2), TRAIL initiates the formation of TRAIL DISC and induce the apoptosis. In addition, three other receptors, DcR1 (TRAIL-R3), DcR2 (TRAIL-R4), and the soluble TNFR family member osteoprotegerin (OPG) can bind to the TRAIL to act as