These genes include ERα, ERβ, GPR30, CYP1A2, CYP3A4 and COMT. It was found that expression of ERα mRNA was down-regulated by 3 to 20 folds in almost all of the HCC tumors compared to the corresponding non-tumorous tissues “Fig 2A”. This evidence concerns the gene CYP1A2 and hepatocellular carcinoma.