Antithrombin III is a plasma protein synthesized in the liver and has molecular weight of 58kDa. Antithrombin III is a heparin-binding glycoprotein that acts as the major inhibitor of thrombin. Also it interferes with several plasma proteases, including kallikrein and factors IXa, Xa, XIa and XIIa, thereby playing a central role in regulating coagulation. It is also used as a therapeutic agent in patients with sepsis and disseminated intravascular coagulation. In addition, a number of recent studies have shown that antithrombin III has antiinflammatory properties, which are independent of its effects on coagulation.