Apoptotic adaptor molecule that recruits caspase-8 or caspase-10 to the activated Fas (CD95) or TNFR-1 receptors. The resulting aggregate called the death-inducing signaling complex (DISC) performs caspase-8 proteolytic activation. Active caspase-8 initiates the subsequent cascade of caspases mediating apoptosis By similarity. Involved in interferon-mediated antiviral immune response, playing a role in the positive regulation of interferon signaling By similarity.Zhang J., Mol. Cell. Biol. 16:2756-2763(1996).Hsu H., Cell 84:299-308(1996).Carninci P., Science 309:1559-1563(2005)