Moreover, while MK571 was more potent than bile acids at increasing doxorubicin uptake into ABCC1-expressing doxorubicin-resistant tumour cells in our study, our findings also show that at a lower but equally effective concentration of MK571 (80 μM) also increased doxorubicin uptake into docetaxel-resistant MCF-7TXT10 cells (Fig. 1). This evidence concerns the gene ABCC1 and neoplasm.