CEBPB and Splenomegaly: The few young adult Cebpa+/−; Cebpb−/− (or α+/−; β−/−) mice obtained showed a dramatic skin phenotype (Fig. 4a), reduced body weight (Fig. 4b), reduced fat pad weight (Fig. 4c) with fat pad lipoatrophy (Fig. 4a), increased liver weight (Supplementary Fig. 4a), and splenomegaly (Supplementary Fig. 4b), and had to be euthanized within 2–3 months because of severe cachexia, infection, and skin lesions.