To further elucidate how E2 exerts its suppressive effect on HCC cells, the cells were transfected ERα, ERβ, GPR30, CYP1A2, CYP3A4, or COMT DNA and overexpression of these genes alone did not significantly influence HCC cell proliferation “Fig 3A”. Here, CYP3A4 is linked to hepatocellular carcinoma.