PTPRN and type 1 diabetes mellitus: Autoantigens have been of interest in T1D for treating the autoimmune component of the disease coinciding with the discovery of autoantibodies and T cells specific for GAD (GAD65), insulin, insulinoma-associated protein 2 (IA2), islet-specific glucose-6-phosphatase catalytic subunit related protein (IGRP), zinc transporter 8 (ZnT8), and others (64).