mTOR is short for the mammalian target of rapamycin. It is also sometimes called the mechanistic target of rapamycin or FK506-binding protein 12-rapamycin-associated protein 1 (FRAP1). mTOR is a serine/threonine protein kinase, which means it’s an enzyme that modifies other proteins.
mTOR contributes to cell growth, metabolism, and other critical cellular functions. mTOR also plays important roles in the brain, liver, and muscles.