TGM2 and dermatitis herpetiformis, familial: To gain insight into the origin of TG3‐specific auto‐antibodies and understand their connection to the anti‐TG2 response, we here characterize TG3‐binding auto‐antibodies in DH patients by assessing serum antibody reactivity and by generation of monoclonal antibodies (mAbs) from TG3‐binding duodenal plasma cells.