CD4+CD25+CD127dim/− Tregs were purified from 6 controls, 10 T2DM patients, 12 CHB patients, and 8 CHB + T2DM patients and were stimulated with either 10 ng/mL or 100 ng/mL recombinant human IL-15 for 24 hours to analyze the potential mechanism of IL-15-induced Tregs regulation. mRNA expressions corresponding to IL-15Rα and immune checkpoint molecules were semi-quantified by real-time PCR. This evidence concerns the gene CD4 and type 2 diabetes mellitus.