KR inhibits AML engraftment in NOD/SCID model. (A) Experimental design of ex vivo treatment. AML or Lin⁻ CB cells were treated overnight with DMSO vehicle (black), 10μM KR (white), or 5μM PTL (gray), and injected into irradiated NOD/SCID mice. Eight weeks later, the surviving mice were killed and human leukemia or normal hematopoietic cell engraftment (CD45⁺) was measured in the injected right femur. (B) Leukemic engraftment by 2 of 4 AML samples was inhibited by KR treatment. (C) Normal hematopoietic engraftment from 5 Lin⁻ CB pools was inhibited by KR and PTL treatment (*P < .05 and **P < .01).