In rats, CYP2E1 activity significantly declined with liver fibrosis progression to HCC, yet higher activity correlated with more severe HCC, suggesting CYP2E1 hyperactivity is a risk factor for the progression of liver fibrosis to HCC.136Thus, CYP2E1 may play different roles in various stages of HCC development, and further in-depth research is needed. The gene discussed is CYP2E1; the disease is hepatocellular carcinoma.