Prkar1a+/−, Prkar2a+/−, Prkar2a−/−, Prkar2b+/− and wild type (WT) mice were necropsied when they developed splenomegaly, lymphadenopathy (at any age) or when moribund between 5 and 25 months of age. The gene discussed is PRKAR2B; the disease is Splenomegaly.