The FASLG gene (FASLG stands for "FAS ligand") is a protein-coding gene located on chromosome 1q24.3. Alternatively spliced transcript variants have been described. The protein encoded by the FASLG gene is a cytokine that binds to the TNFRSF6/FAS receptor. This receptor transmits an apoptotic signal into cells.
The FASLG protein is involved in apoptosis mediated by cytotoxic T cells. It is also involved in apoptosis mediated by natural killer cells and in the development of T cells. It initiates activation-induced cell death(AICD) in antigen-activated T cells, which contributes to the termination of immune responses. TNFRSF6/FAS-mediated apoptosis also plays a role in the induction of peripheral tolerance.