Kinase TOR (target of rapamycin), discovered as a target of antibiotic rapamycin, the evolutionarily conservative serine/threonine kinase that integrates numerous extra-cellular and intracellular signals, regulating cell growth, protein synthesis and metabolism. Mammalian kinase (mTOR) exists in two complexes: the rapamycin-sensitive TORC1 and rapamycin resistant mTORC2, controlling in the cell different programs. Identification of mTOR as integral component PI3/Akt way that deregulated during carcinogenesis, as well as the existence of a cross-talk between the tumor-suppressor p53 cascade and mTOR demonstrates its unique role in the process of neoplastic growth. This review discusses the various aspects of the regulation of the kinase mTOR, the relationship with the general cell-signaling pathways and its use as a target for the cancer, diabetes, obesity, neurodegenerative changes and hereditary syndromes of aging.