EIF4EBP1 and neoplasm: Our data confirm that Rapamycin has a direct effect on inhibition of the mTOR pathway in Wnt-1 transgenic tumor cells in primary cultures and in cell lines derived from these tumors with suppression of proliferation and a decrease in phosphorylated forms of S6K1, ribosomal protein S6, 4E-BP1 and Akt.