CDKN1A and hepatocellular carcinoma: As the function of these critical cellular proteins can be impaired by common causes of chronic liver disease and HCC, including viral hepatitis B and C proteins [14-22], we suggest that disruption of pRb function, and to a lesser extend P21Cip1 and P53 in hepatocytes may represent an additional new mechanism of escape from TGFβ growth inhibition in the inflammatory milieu of chronic liver disease.