MTOR and Insulin resistance: Consistent with the development of mTOR inhibitors as a glucose-lowering agent, mTOR is over-activated in high-fat diet (HFD)-induced obese rodents and induces insulin resistance in the liver and muscle10, 11; whereas the downregulation of mTOR signaling, or the deletion of S6 kinase (S6K), the crucial effector of mTOR signaling, is sufficient to enhance insulin sensitivity in rodents12, 13.