Apoptosis regulator protein which may function as a crucial link between cell survival and cell death pathways in mammalian cells. It acts as an inhibitor of TNFRSF6 mediated apoptosis. A proteolytic fragment (p43) is likely retained in the death-inducing signaling complex (DISC) thereby blocking further recruitment and processing of caspase-8 at the complex. Full length and shorter isoforms have been shown either to induce apoptosis or to reduce TNFRSF-triggered apoptosis. It lacks enzymatic (caspase) activity.Synonyms: CASH, CASP8 and FADD-like apoptosis regulator, CASP8AP1, CLARP, Caspase homolog, Caspase-eight-related protein, Caspase-like apoptosis regulatory protein, Cellular FLICE-like inhibitory protein, FADD-like antiapoptotic molecule 1, FLAME-1, Inhibitor of FLICE, MACH-related inducer of toxicity, MRIT, Usurpin, c-FLIP