For example, the enzymatic activity or expression of MnSOD is frequently downregulated in numerous diseases, such as diabetes and neurodegenerative diseases [30,31,32,33], whereas overexpression of MnSOD protects against pro-oxidant insults resulting from inflammatory cytokines, irradiation, hyperoxic injury, and ischaemia/reperfusion [34,35,36,37,38,39,40]. The gene discussed is SOD2; the disease is diabetes mellitus.