SOD2 and hepatocellular carcinoma: The result shows that low SOD2 protein expression (p = 0.005), higher serum AFP (p = 0.002), larger tumor size (p = 0.010), multiple tumors (p < 0.001), tumor embolus (p = 0.004) advanced TNM (p = 0.001) and BCLC stage (p < 0.001) are predictors for poor OS of HCC patients (Table 2).