FLT3 and acute myeloid leukemia: Given the proven importance of the CXCL12/CXCR4 axis in AML, particularly with FLT3-ITD, and the rapid emergence of resistance to FLT3 inhibitors, FLT3-ITD-AML might represent the subset of AML that derives the most benefit from the combination of FLT3 and CXCR4 inhibitors.