SOD1 and liver dysplastic nodule: Oxidative stress is considered to be an etiologic factor in the pathogenesis of DN, and an imbalance between excess generation of pro-oxidants and antioxidants including SOD, CAT, GPx, and GSH is believed to play an important role in modulating kidney tissue damage such as renal tubular cell death, tubulointerstitial fibrosis, and glomerular mesangial expansion (Singh et al., 2011).