PTPRC and type 1 diabetes mellitus: To aid in concordance between studies of T1D histopathology, a consensus definition of CD3+ T-cell infiltration was established in 2013: T1D was defined by the presence of ≥3 islets without β-cells (also called pseudoatrophic islets) and CD3+ T-cell infiltration as the presence of ≥3 islets with ≥15 CD45+ cells within or touching the perimeter of an islet.3