MTOR and cancer: Phosphorylation is mitigated by downstream effects of the mammalian target of the rapamycin (mTOR) pathway with dysregulation being apparent in various cancers.86 p-S6 and p-eIF4E were discovered in 197487 and 1976,88 respectively, with elevated levels of either protein being indicative of uncontrolled cell growth87 from increased protein synthesis.