SOD1 and endothelial dysfunction: The use of febuxostat, an inhibitor of xanthine oxidase enzyme, is effective in reducing the burden of oxidative stress and endothelial dysfunction in ESRD patients; in a randomized controlled trial including 57 ESRD patients, randomized to receive either oral 40 mg febuxostat or standard of care, febuxostat was able to significantly decrease serum malondialdehyde (MDA), as a marker of free radical activity, and increase superoxide dismutase (SOD) levels, as a marker of antioxidant enzymatic activity [34].