It is noteworthy that serum SOD was significantly different in the HC and CKD 1–3 groups compared to the CKD 4–5 group (HC vs CKD 4–5, t ═ 7.593, P < 0.0001; CKD 1–3 vs CKD 4–5, t ═ 5.618, P < 0.0001). This evidence concerns the gene SOD1 and chronic kidney disease.