The derivation of Bim-deficient lpr mice in 2008 cemented this conclusion: compared with single knockouts alone, loss of both Bim and Fas resulted in extraordinary lymphoproliferation with massive lymphadenopathy, splenomegaly and DNT accumulation, coupled with early-onset, fatal lupus-like autoimmunity (Hughes et al., 2008; Hutcheson et al., 2008; Weant et al., 2008). The gene discussed is FAS; the disease is Autoimmunity.