Tbk1D135N/D135NIkkeK38A/K38ARipk1wt/D138N and Tbk1-/-Ikke-/-Ripk1wt/D138N mice showed splenomegaly and a pronounced expansion of monocytes and neutrophils in peripheral blood and lymphoid tissues, which was largely dependent on RIPK1 kinase activity as this phenotype was strongly, but not completely, suppressed in a Ripk1D138N/D138N background. This evidence concerns the gene TBK1 and Splenomegaly.