FAS, also named as CD95, APO-1, APT1, FAS1 and TNFRSF6, is a receptor for TNFSF6/FASLG. It is a cell surface receptor belonging to the TNF receptor superfamily, can mediates apoptosis by ligation with an agonistic anti-Fas antibody or Fas ligand. Stimulation of Fas results in the aggregation of its intracellular death domains, leading to the formation of the death-inducing signaling complex (DISC). FAS-mediated apoptosis may have a role in the induction of peripheral tolerance, in the antigen-stimulated suicide of mature T-cells, or both. The secreted isoforms 2 to 6 block apoptosis (in vitro). This anti-Fas monoclonal antibody can be used to induce apoptosis in cell cultures through Fas by imitating the Fas-ligand.