These include IgM-associated polyneuropathy [3], [4], [5], multiple sclerosis [6], dermatomyositis [7], rheumatoid arthritis (RA) [8], [9], relapsing-remitting multiple sclerosis, and systemic lupus erythematosus (SLE) [10], [11], [12]. The gene discussed is CD40LG; the disease is systemic lupus erythematosus.