PDCD1 and type 2 diabetes mellitus: Noteworthy, the percentage of PD-1+ Th1-like Treg was decreased in Pre-T2D (41% ± 8.1 vs. nOB: 56% ± 12.3; Figure 8H and Supplementary Table S5), while the PD-1+ Th1/17-like was reduced in the Pre-T2D group (36% ± 10.1, p < 0.05 vs. nOB; Figure 8M and Supplementary Table S5) and Class II obesity (39% ± 13.9), in comparison to the nOB (49% ± 13.3), with sequential increases in Classes III and IV (Supplementary Table S5).