RIPK3 and Splenomegaly: At age of 16 weeks, similar as RIPK3 and Caspase8 deficient mice, the Ripk1Y383F/Y383FRipk3−/−Caspase-8−/− mice also showed dramatic splenomegaly which is caused by massive infiltration of CD3+B220+ lymphocytes (Supplementary Fig. 6d, e).