FLT3 and acute lymphoblastic leukemia: For example, we previously demonstrated that inhibition of CXCR4 with plerixafor enhances the cytotoxic effects of FLT3 inhibitors in MLL-R infant ALL[9] and chemotherapy in AML with internal tandem duplications of FLT3.[10] CXCR4 inhibition as a chemosensitization strategy has also moved into clinical trials.