The X protein （HBx） of Human hepatitis B virus （HBV） acts as an indirect transcriptional transactivator to regulate the expression of many viral and cellular genes, as well as playing a critical role in pathogenesis and the deve!opment of Hepatocellular carcinoma （HCC）. Here we described the biological effects of HBx in association with four cellular factors, including inflammatory factors （COX-2 and iNOS）, oncoprotein （Ras）, and a newly identified tumor suppressor （YueF）. The characteristics of these effectors, which might be associated with hepatocellular carcinoma, are also discussed.
