The findings that anti-TG3 serum antibodies primarily belong to the IgA class and that TG3-specific plasma cells are present in the gut lamina propria of DH patients suggest that the response has a mucosal origin and that T cell-B cell interactions take place in gut-associated lymphoid tissues8,11,12. The gene discussed is CD79A; the disease is dermatitis herpetiformis, familial.