PGP and hepatocellular carcinoma: Although the present study shows that PACC and PADF can reverse MDR in BEL-7402/5-FU cells, the mechanism here clarified could only be justified by the protein and gene expressions of P-gp, MRP, and LRP; thus, further studies about drug resistance-associated enzyme systems are still needed to provide an experimental and theoretical basis to overcome MDR and to improve the efficacy of the combination of PACC and PADF with chemotherapeutic drugs in HCC cells.