These antigens represent different aspects of ARF disease mechanisms including an immune cell signalling protein [PTPN2 (41)], a central component of the extracellular matrix in muscle fibre [DMD (42)] and a protein abundantly expressed in cardiomyocytes and chondrocytes during osteoarthritis [ANXA6 (43, 44)]. Here, PTPN2 is linked to rheumatic fever.