In line, inhibiting HDAC1, either by small molecule inhibitors or by siRNA, increased the constitutive expression of CYP1A1 in human breast MCF-7 or cervical cancer Hela cells [198], in human HepG2 [201] and in murine Hepa1c1c7 liver carcinoma cells [240]. This evidence concerns the gene CYP1A1 and hepatocellular carcinoma.