Visualized results showed that the subgroup of C03 subset significantly increased in the T2D-DN group associated with the upregulation of immunological inhibitory receptors, such as cytotoxic t-lymphocyte antigen 4 (CTLA-4) and program death-1 (PD-1) (Figures 2G, H). This evidence concerns the gene CTLA4 and type 2 diabetes mellitus.