Overview of the PI3K/Akt/mTOR pathway (reproduced from [9], with permission). RTK = receptor tyrosine kinase, P = phosphate, IRS1 = insulin receptor substrate-1, PIP2 = phosphatidylinositol 4,5-bisphosphate, PIP3 = phosphatidylinositol 3,4,5-trisphosphate, PI3K = phosphatidylinositol 3-kinase, Akt = activated protein kinase B, mTOR = mammalian target of rapamycin, rictor = rapamycin-insensitive companion of mTOR, raptor = regulatory-associated protein of mTOR, TSC = tuberous sclerosis complex, Rheb = Ras homolog enriched in brain, GDP = guanosine diphosphate, GTP = guanosine triphosphate, S6K1 = ribosomal S6 kinase 1, 4EBP1 = 4E-binding protein 1, eIF4e = eukaryotic translation initiation factor 4E.