Previous studies have demonstrated that IgA- or IgG-coated bacteria are increased in the intestinal lumen of IBD patients [19–21] and that colonization of IgA-coated bacteria in germ-free mice has been more prone to the occurrence of experimental colitis [21, 22], thus IgA and IgG may play vital roles in the pathogenesis of IBD. The gene discussed is CD79A; the disease is inflammatory bowel disease.