To confirm this hypothesis, we first evaluated the abundance of the GTP-Rac1 complex, which indicated the activation of Rac1, and found that the relative abundance of the GTP-Rac1 complex increased by more than 1.2-fold in U937 and HL60 cells after AML cells were transfected with miR-4458 inhibitor. This evidence concerns the gene RAC1 and acute myeloid leukemia.