PRF1 and type 1 diabetes mellitus: Although single-cell analysis of differentially expressed genes in the MAIT cell cluster (cluster 6 in Supplemental Figure 3B) showed limited differences between Treg-T1D and TILT samples at day 0, by day 7, after the first course of IL-2, activation markers such as PRF1, CD69, GZMA, CXCR4, and killer cell lectin like receptor B1 were upregulated in the MAIT population in the circulation of TILT patients (Figure 5E).