Human mechanistic evidence remains limited; however, in a 63-year-old man with well-controlled type 2 diabetes treated with nivolumab for renal cell carcinoma with pancreatic metastasis, histology from non-tumorous pancreas revealed dense T-cell infiltration dominated by CD8+ over CD4+ cells, with few B cells or macrophages, implicating CD8+ T cells as principal effectors in CIADM pathogenesis (51). The gene discussed is CD8A; the disease is type 2 diabetes mellitus.