PTPRN and type 1 diabetes mellitus: In terms of T-cell reactivity, distinct profiles of CD4 T-cell autoimmunity could be identified in children with T1D, where some showed immune reactivities to all four tested islet autoantigens (PPI, IA-2, DRiP and GAD65), whereas others responded to none, and half of the children reacted with 2-3 islet autoantigens.