ABCB1 and acute myeloid leukemia: It has been shown that increased expression of the ABCB1 gene also known as P-glycoprotein (Pgp) or multidrug resistance protein 1 (MDR1), a member of the ABC transporter family that can efflux drugs out of the cell, is strongly associated with resistance to chemotherapy and FLT3 inhibitors in AML [89, 90].