Biochemical analysis results show that SOD activities and GPX activities (p < .001, respectively, Figure 3a,b) in cerebral cortices and hippocampi of rats in the saline treatment model group decreased significantly, while the MDA levels and protein carbonyl compound levels (p < .001, respectively, Figure 3c,d) increased significantly, compared with those in the sham‐operation group, indicating that CCH causes oxidative stress damage. The gene discussed is SOD1; the disease is columnar cell hyperplasia of the breast.