In the current study, two human liver cell lines with either wild type or null p53 status, and four primary HCC cell lines with either wild type or mutant p53, were treated with a recombinant adenoviral vector carrying TK in combination with the prodrugs GCV (rAdV-TK/GCV), rAdV-p53, and rAdV-ASPP2, either individually or in combination, in order to better understand the therapeutic mechanisms of HSV-TK/GCV in HCC. The gene discussed is TKT; the disease is hepatocellular carcinoma.