In our case, the history of autoimmune pancreatitis and asthma, normal level of IgA (51 mg/dL at the first diagnosis of IgG4-RD) and CRP, high level of IgE (267.5 mg/dL at first diagnosis of IgG4-RD) and asymptomatic condition suggest IgG4-RD rather than MCD. The gene discussed is CD79A; the disease is asthma.