PDCD1 and obesity due to melanocortin 4 receptor deficiency: Looking deeper into the CCR5−CCR6−CD4+CD8+ T cells, they were markedly more activated in individuals with obesity (nOB: 17% ± 15.5 vs. OB: 30% ± 19.1, p < 0.05), especially Pre-T2D and T2D (p < 0.05 vs. nOB; Supplementary Table S9), and displayed a decreased percentage of PD-1+ cells (nOB: 48% ± 28.5 vs. OB: 31% ± 17.1, p = 0.085; Supplementary Table S9).