ABCB1 and acute promyelocytic leukemia: The ability of DOX to inhibit the growth of human promyelocytic leukaemia HL60 cell line as well as its MDR sublines exhibiting two different phenotypes of MDR related to the overexpression of P-glycoprotein (HL60/VINC) or MRP1 (HL60/DOX) was studied in the presence or in the absence of exogenously added NADPH and CPR.