Fas Ligand, also known as FASLG and CD95L, is the ligand for FAS. It is a transmembrane protein which binds to TNFRSF6/FAS. Interaction of FAS with fas Ligand is critical in triggering apoptosis of some types of cells such as lymphocytes. Fas Ligand may be involved in cytotoxic T-cell mediated apoptosis and in T-cell development. TNFRSF6/FAS-mediated apoptosis may have a role in the induction of peripheral tolerance, in the antigen-stimulated suicide of mature T-cells, or both.