10 ng/mL of IL-15 did not affect PD-1 mRNA relative levels in Tregs in any group (p > 0.05, Figure 4D), while 100 ng/mL of IL-15 dampened PD-1 mRNA expression in controls, T2DM, and CHB patients (p < 0.05, Figure 4D). The gene discussed is IL15; the disease is type 2 diabetes mellitus.