Overexpression of ABCB1, ABCC1 (multidrug resistance-associated protein 1, MRP1), ABCC3 (MRP3), and ABCG2 (breast cancer resistance protein, BCRP) genes is associated with poor prognosis in AML patients [8,9,10,11]. The gene discussed is ABCB1; the disease is acute myeloid leukemia.