IGHM and diabetes mellitus: B cells seem to contribute to APECED disease, as demonstrated by B cell–deficient Aire–/– mice that had ameliorated multiorgan infiltration (36), by B cell depletion in NOD Aire–/– mice that led to diabetes onset delay (43), and by NOD Aire–/–Ighm–/– mice that had partial amelioration of autoimmune lung disease (19).