Majority of IgE+ cells arise from somatically hypermutated IgG1-expressing cells as demonstrated from analysis of Ig heavy regions in peripheral blood of patients with allergy (50)Binding of IgG1-containing immunocomplexes to the IgG inhibitory Fc gamma receptor (FcγRIIB) suppresses complement C5aR-mediated inflammatory signaling in allergy (54). The gene discussed is IGHE; the disease is allergic disease.