RPS6 and acute lymphoblastic leukemia: To determine why dual inhibitors targeting PI3K/mTORC1/C2 more potently suppressed cell proliferation and induced cell death than the selective inhibitors of PI3K and mTORC1, respectively, we analyzed the phosphorylation level of AKT, S6 and 4E-BP1 in ALL-LTCs following to the different inhibitors (Figure 5C and 5D).