For this purpose, 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 investigated in the presence of exogenously added CPR and NADPH. Here, ABCB1 is linked to acute promyelocytic leukemia.