To assess the functional aspects of cytotoxic T cells, we calculated the cytotoxicity score for CD4 Tcyt and CD8 Tem using cytotoxic genes (PRF1, GZMH, and GZMK) and observed higher cytotoxicity scores in T2D patients compared to non-diabetes (Figure 3D). The gene discussed is CD8A; the disease is type 2 diabetes mellitus.