We previously revealed that FLT3-ITD activates the mTORC1/S6K/4EBP1 pathway cooperatively through the STAT5/PIM and PI3K/AKT pathways to enhance proliferation and survival of AML cells [12,13], which was extended in the present study by revealing that the MEK/ERK/RSK pathway also works cooperatively with these pathways. This evidence concerns the gene RPS6KA3 and acute myeloid leukemia.