mTOR (mammalian rapamycin target protein) is a member of the phosphatidylinositol 3-kinase-associated kinase family and is a key component of two different protein complexes, mTORC1 and mTORC2, which phosphorylate different substrate groups to regulate different cellular processes. mTOR1 can sense and integrate a variety of nutritional and environmental factors, including growth factors, energy levels, cellular stress, and amino acids.