PGP and cancer: The wild cancer cells MX-1 and taxol-resistant MX-1/T cells were used to investigate the effect of P-gp inhibition by flavonoids (isosinensetin 8.4 μM, tangeretin 25.3 μM, sinensetin 37.8 μM, sciadopitysin 106.8 μM, oroxylin A 155.6 μM) on taxol (75μM) cytotoxicity.