RPS6KB1 and lung cancer: To examine whether the ability of pharmacological VC to inhibit the mTOR pathway is unique to lung cancer cells, we also treated colon cancer cells (DLD1 and HCT116) with different concentrations of pharmacological VC and again found that S6K, S6, 4EBP1, and AKT phosphorylation were inhibited (Fig 1C and 1D).