PGP and acute myeloid leukemia: Resistance of CD34+ AML cells to DNR has been displayed in CD34+ cells KG-1a and KG-1.22 Resistance to DNR may not only come from P-gp-mediated efflux but also due to its distribution feature in CD34+cells.23, 24In addition, PI3K pathway activity can play role in the protection of cell against DNR.25 Actually, survival signaling and evasion process of apoptosis should be disrupted with a drug to beat down cell resistance.