Participants with obesity and insulin resistance, not taking medication for T2D, showed a higher percentage of CD4+CD8+ T cells within T cells (IRn: 2.8% ± 1.1; Pre-T2D: 2.2% ± 2.0) compared to T2D patients under treatment (1.6% ± 1.9, p < 0.05 for IRn vs. T2D; Figure 5 and Supplementary Table S2). The gene discussed is CD8A; the disease is obesity due to melanocortin 4 receptor deficiency.