CASP8 and neoplasm: Moreover, analysis of the apoptosis process induced by TRAIL in human colon cancer cell line SW620 revealed that although caspase-8 activation and subsequent tBid formation was triggered in tumor cells upon treatment with TRAIL, up-regulating Bcl-2, Bcl-xL and Mcl-1 blocked TRAIL-mediated apoptosis in treated tumor cells (41).