Thus, we believe that the onset of type 1 diabetes contributed to the elevation of CD8+ cytotoxic T cells in the pancreatic lymph nodes, while the prolonged stabilization of PD-L1 on the pancreatic β cells could not only reverse the infiltration of CD8+ T cells, but restrain the activity of autoreactive T cells in the pancreatic lymph nodes. This evidence concerns the gene CD8A and type 1 diabetes mellitus.