Our cross-sectional study in pancreas of humans with T1D demonstrated no T cell infiltration (as adjudged by staining for the presence of CD45) in or around hormone-negative endocrine cells, suggesting that direct interaction of autoimmune T cells with β cells might not be responsible for alterations in β cell identity in humans with T1D; however, it is also possible that CPHN cells are not yet expressing surface antigens that attract autoimmune T cells [87••]. Here, PTPRC is linked to type 1 diabetes mellitus.