CD4 and type 2 diabetes mellitus: In the analysis of iNKT cells within CD8+ cytotoxic, CD4+, and CD4-CD8- DN T-cell subsets — defined as CD161+TCR Vα24-Jα18+ double-positive cells (gating strategy in Supplementary Figure 2M–O) — and comprising less than 0.1% of all CD3+ T cells, we observed a general trend towards reduction in both T1D and T2D, reaching statistical significance for CD4+ iNKT cells in T2D compared with healthy controls (p = 0.0101, Figures 4I, J, Table 5, Supplementary Table 1).