As autoreactive cytotoxic CD8+ T cells drive pancreatic β-cell destruction in diabetes, it seems plausible that changes in the frequency and activation (CD69+ and IFN-γ+) of CD8+ T cells observed in NOD.Ifih1R/R mice likely contributed to the accelerated diabetes observed in NOD.Ifih1R/R females. This evidence concerns the gene CD69 and diabetes mellitus.