PIM1 and acute myeloid leukemia: Taken together, the present study suggests that RSK1 may protect FLT3-ITD-positive AML cells from apoptosis induced through the intrinsic mitochondrial pathway by negatively regulating Bad, as well as BIM, and by upregulating Mcl-1 or other anti-apoptotic proteins through activation of the mTORC1/eIF4F pathway and eIF4B cooperatively with the STAT5/PIM and PI3K/AKT pathways (Figure 7).