Alpha-2-antiplasmin, also called Serpin F2, is a serine protease inhibitor (serpin) responsible for inactivating plasmin, and an important enzyme participates in fibrinolysis and degradation of other proteins. In liver cirrhosis, there is decreased production of alpha 2-antiplasmin, leading to decreased inactivation of plasmin and an increase in fibrinolysis. Serpin F2 is major expressed on liver and kidney. Some other tissues such as muscle, intestine, central nervous system, and placenta also express Serpin F2 mRNA at a moderate level indicated that it is a key regulator of plasmin-mediated proteolysis in these tissues.