PTPRN and dermatomyositis: These include autoantibodies to Histidyl-tRNA synthetase (Jo-1), Anti-Islet Cell Antigen 512 (IA-2), Tissue Transglutaminase 2 (tTG), Dermatomyositis specific autoantigen Mi-2 (Mi-2), thyroid peroxidase (TPO) and SAE1/SAE2 (Figure 3A).