To delineate the functional relevance of the observed positive correlation between natural C-terminal truncated HBx and CD133 in HCC cell lines, we performed various in vitro assays to examine the ability of C-terminal truncated HBx to modify cancer and stem cell properties, including their abilities to form spheres and serially passage in 3D culture systems (clonogenic potential), to resist chemotherapy and targeted therapy treatment, as well as to promote cell migration and capillary tube formation in endothelial cells. The gene discussed is PROM1; the disease is cancer.