Of note, HL-60 cells have been reported to acquire resistance to several drugs used in AML chemotherapy including cytarabine, anthracyclines doxorubicin, and daunorubicin as well as arsenic trioxide via mechanisms related to modulation of P-gp, MRP1, or BCRP expression [92,93,94]. The gene discussed is ABCG2; the disease is acute myeloid leukemia.