TNFSF10 and cancer: Each of DRs contains a cytoplasmic functional death domain.4, 5, 6 Following engagement with the DRs, TRAIL triggers cell death via both extrinsic and intrinsic apoptosis pathways.7 As a result of its selectivity toward tumor cells, both TRAIL and TRAIL-R agonistic antibodies (mapatumumab and lexatumumab) against its receptors are currently in clinical trials for treatment against cancer.8, 9, 10