TP53 and hepatocellular carcinoma: According to data obtained from an in vitro HBV infection system, ATRA downregulated the levels of HBx, an activator of HBV replication [11], in HepG2-NTCP cells but not in Hep3B-NTCP cells (Figure 1A,B), suggesting a possible role of HBx in the p53-dependent inhibition of HBV replication by ATRA in human hepatoma cells.