Given that the frequency of many autoimmune diseases are elevated in females (28, 29), anti-IgM titers in IgHEL+HOD+ mice were compared across gender; female IgHEL+HOD+ mice had significantly higher titers of anti-HOD IgM autoantibodies, compared to their male littermates thereby accounting for the bimodal distribution of autoantibodies (Figure 4C). The gene discussed is CD40LG; the disease is autoimmune disease.