In both the HC and T1D cohorts (Figure 1), increasing years of age (effect of 0.32 [95% CI: 0.20, 0.45], P = <0.0001) and CMV seropositivity (effect of 3.67 [95% CI: 2.06, 5.28], P = <0.0001) were significantly associated with TIGIT+KLRG1+ CD8 T cell frequency in a linear mixed-effects model. This evidence concerns the gene KLRG1 and type 1 diabetes mellitus.