RPTOR and acute lymphoblastic leukemia: STATs are largely dispensable for the survival of Ph-like ALL cells. The depletion of either MTOR or RPTOR, which encode components of the mTORC1 complex, significantly altered cell fitness regardless of RAS mutation status. This suggests that the mTORC1 pathway plays a key role in the survival of Ph-like ALL cells. Treatment should be stratified according to co-occurring mutations.