The mTOR (mammalian target of rapamycin) is central regulator of an evolutionary conserved signalling pathway which controls cellular metabolism, growth and proliferation.Deregulation of mTOR-coordinated signalling has been associated with various human pathologies, including diabetes, inflammation and cancer.Rapamycin, a naturally occurring mTOR inhibitor, and its homologues have been currently tested as anti-cancer drugs in numerous clinical trials.In contrast to yeast which have two TOR genes (TOR1 and TOR2), there is only one gene encoding mammalian TOR.The diversity of TOR-mediated signalling in mammals is compensated by the existence of two multienzyme complexes, mTORC1 and mTORC2, whose regulatory components and downstream effects mirror in part signalling mediated in yeast by TOR1 and TOR2 pathways.The mechanisms by which mTOR sensors and controls energy metabolism and cell growth are relatively well understood, while molecular events defining mTOR-mediated proliferation remain to be elucidated.We have recently defined molecular events responsible for mediating mTOR-driven proliferation and oncogenic transformation.Furthermore, a functional link between mTOR/S6K pathway, Coenzyme A biosynthesis and energy metabolism have been identified in our laboratory.The progress on these topics will be discussed.