BAFF overexpression in the mouse induces multi-organ autoimmune disease, including systemic lupus erythematosus (SLE) and IgA nephritis like disease manifestations characterized by increased anti-ds-DNA and anti-nuclear autoantibody production, renal Ig complex deposition, and raised serum IgA, IgG, and IgE levels (21, 22). The gene discussed is TNFSF13B; the disease is systemic lupus erythematosus.