FAS and autoimmune lymphoproliferative syndrome: Casp8−/−Ripk3−/− and Casp8−/−Mlkl−/− mice [11], characterized by splenomegaly with a marked accumulation of CD3+CD4−CD8−B220+ T cells, resemble the deficiency of FAS ligand (FasL, CD95L) [28] or FAS (CD95) [29, 30] in mice or the autoimmune lymphoproliferative syndrome (ALPS) in humans [31].