SOD1 and type 2 diabetes mellitus: Furthermore, it was observed that there was significantly elevated OS activity in the T2DM+DR patients versus the CG, as reflected by the MDA/TBARS (p = 5.97 × 10−24), SOD (p= 3.62 × 10−16), and GPx (p = 0.025) expression levels (Figure 4A–C, respectively).