AKT1S1 and acute lymphoblastic leukemia: Because the PIM protein kinases have been shown to regulate the phosphorylation of 4E-BP1 [19], PRAS40 [20], and also there is evidence that phosphoinositide-3 kinase (PI3K)–AKT and mammalian target of rapamycin (mTOR) pathways are activated in T-ALL [21, 22], we investigated whether PIM inhibitor treatment blocks the mTOR pathway in these leukemic cells.