mTOR (Mammalian Target of Rapamycin) is a member of the PI3K-related kinase family, composed of two complexes, mTORC1 and mTORC2. It contains a catalytic domain and multiple regulatory regions, primarily located in the cytoplasm. mTOR regulates cell growth, metabolism, survival, and autophagy, serving as a central node linking nutrient signals, energy status, and growth factor signaling. By activating S6K1 and inhibiting 4E-BP1 and other downstream effectors, mTORC1 is involved in protein synthesis and cell cycle progression, while mTORC2 participates in the regulation of cell survival, cell cycle, and cell polarity. mTOR is expressed in multiple tissues, and its overactivation or mutations are associated with cancers, metabolic disorders, and neurodegenerative diseases.