ATP5F1B and hepatocellular carcinoma: Thus, we tested whether ATP5B could interact physically with NTCP by using the transient expression of NTCP V5His in HEK293T cells, since the efficiency of transfection of NTCP V5His into HepG2 or the other human HCC-derived cell lines was extremely poor, and there was no suitable antibody to detect NTCP in Western blot analysis.