Notably, the negative correlation between DDAH2 and CD8+ T cells was significant in both diseases, possibly reflecting its suppression of T cell toxicity through NO signaling (Huang et al., 2021a), a mechanism that may have a double-edged effect in the autoimmune injury of T2DM and the immunosuppressive phase of sepsis. The gene discussed is DDAH2; the disease is type 2 diabetes mellitus.