ALPS is due to various mutations of the FAS/FAS ligand pathway (FAS (also known as TNFRSF6), FASLG, and CASP10 (caspase 10)) leading to inefficient FAS-mediated apoptosis of T cells responsible for the survival of activated T cells and the emergence of autoreactive T cells. This evidence concerns the gene CASP10 and autoimmune lymphoproliferative syndrome.