C9orf72−/− knock-out mice indeed exhibit dysregulation of the immune system, age-dependent inflammation characterized by a cytokine storm, neuroinflammation and features of autoimmunity like systemic lymphadenopathy, splenomegaly, pseudothrombocytopenia, high levels of autoantibodies and membrano-proliferative glomerulonephritis reminiscent of systemic lupus erythematosus (SLE). This evidence concerns the gene C9orf72 and Splenomegaly.