For example, the SOD activity in the serum of gastric carcinoma is 27.6 ± 6.6 U mL−1 (Naidu et al., 2007), while SOD activity in the serum of patients with intestinal cancer is 79.35 ± 15.66 U mL−1 (Lee et al., 2006). Here, SOD1 is linked to gastric carcinoma.