Although, we could not analyze mouse IgG2a, IgG2b or IgG3 because of limited serum samples, Funakoshi et al [31] described in a study on pemphigus patients that IgG subclasses other than mouse IgG1 may decrease more than IgG1, which may help to explain this finding. The gene discussed is IGHG3; the disease is pemphigus.