TBK1 and Splenomegaly: On necropsy, Ikke-/-Tbk1-/-Ripk1wt/D138N and IkkeK38A/K38ATbk1D135N/D135NRipk1wt/D138N mice, but not Tbk1-/-Ripk1wt/D138N and Tbk1D135N/D135NRipk1wt/D138N mice, displayed splenomegaly, which was partially suppressed by homozygous Ripk1D138N/D138N genetic background (Fig. 2a).