Finally, decreased CYP2E1 expression was observed in the tumor tissues of HCC patients and its expression level in tumors was negatively correlated with the serum level of total bile acids (TBA) and gamma-glutamyltransferase (GGT).<h4>Conclusions</h4>CYP2E1 downregulation contributes to CA-induced HCC development presumably through autophagy regulation. The gene discussed is CYP2E1; the disease is neoplasm.