In T cells, the Cd8 coding genes (Cd8a and Cd8b1) were down-regulated dramatically in the T2D group (Fig. 5C), while those genes that inhibited Th17 cell differentiation, including Tbx21, Il2rb, Runx1, Ifngr1, and Jak1, were increased in the T2D group (Fig. 5D; Fig. S6). Here, CD8A is linked to type 2 diabetes mellitus.