CXCR4 and leukemia: Another CXCR4 inhibitor, AMD3465, interfered with chemotaxis of AML cells toward SDF1 in vitro, prevented SDF1-induced activation of survival pathways in AML cells, caused mobilization of human leukemia cells in immunodeficient mouse xenografts, and enhanced the activity of sorafenib in Flt3-positive AML [22].