Interestingly, hepatocellular carcinoma cells transfection with HBV pX protein contributes to the expansion of a subpopulation within the total HCC cell pool characterized by an increased tumorigenecity, self-renewal, stemness-associated genes expression such as CD133, Nanog, SOX-2, and OCT-4, and an enriched chemoresistance toward pirarubicin, oxaliplatin, and hydroxycamptothecin (214). This evidence concerns the gene POU5F1 and hepatocellular carcinoma.