TP53 and hepatocellular carcinoma: We therefore cloned the wt p53 gene from a human hepatoblastoma cell line, HepG2, into a human hepatocellular cell line, Hep3B, using a retrovirus-mediated tet-regulated gene expression system (RevTet-Off) and established a HCC cell line with tightly controllable, doubly-stable expression of the wt p53 gene.