For the AF patients, Spearman correlation analysis indicated that there was a significantly negative correlation between plasma MnSOD levels and LAD (r = −0.232, p = 0.008) and a positive correlation between plasma MnSOD levels and RDW-CV (r = 0.214, p = 0.014), but no statistically significant correlation between MnSOD and other parameters (Table 5). The gene discussed is SOD2; the disease is atrial fibrillation.