Furthermore, in combinatorial treatment, PH II-7(0.5 μM, much lower than IC50), significantly potentiates ADM and Vincristine (VCR) (Both are substrates of P-gp) against MDR cancer cells (Fig. 2C), Which suggests certain degree of re-sensitization of P-gp overexpressing MDR cells by PH II-7. The gene discussed is PGP; the disease is cancer.