Thrombin activatable fi brinolysis inhibitor (TAFI) is one of the key proteins of fi brinolysis and infl ammation systems. Based on literature data, information is presented on the biological eff ects of TAFI, the mechanisms of its activation, gene polymorphism that determines the duration of its action and activity. Nosological forms are listed, where TAFI is important in the pathogenesis of the development of diseases, its role in experimental and laboratory studies, and the possibility of pharmacological infl uence on the activity of this protein.