PBX1 and acute lymphoblastic leukemia: Hence, to investigate which upstream complexes (MTORC1 or MTORC2) are involved in cell survival and proliferation, we depleted rapamycin-independent companion of MTOR (RICTOR) and regulatory-associated protein of MTOR (RPTOR) using single shRNAs in E2A-PBX1+ B-ALL cells (Supplementary Table S4).