Additional studies showed that +SA mammary tumors grown in syngeneic mice also displayed elevated HIF-1a levels and enhanced Akt/mTOR, p70S6K, and eIF-4E1 activation, and treatment with compound 44, but not its parent compound, δ-tocotrienol, blocked this compensatory response to hypoxic conditions. Here, RPS6KB1 is linked to breast cancer.