FAS and Autoimmunity: Moreover, sophisticated mouse models in which Fas or FasL is only removed from T cells, B cells or dendritic cells all share lymphoproliferation and systemic autoimmune features (Stranges et al., 2007; Mabrouk et al., 2008), underscoring the concept that FAS/CD95 safeguards against autoimmunity by deleting chronically activated, self-reactive lymphocytes and clearing excess APCs.