FLT3 and acute myeloid leukemia: Interestingly, miR-155 is also the most highly dysregulated miRNA in primary FLT3-ITD+ AML cells compared to FLT3-WT AML or normal CD34+ hematopoietic stem and progenitor cells [1, 2], and has been implicated in regulating the survival and growth of FLT3-ITD+ cells [19].