Factor IX

Factor IX is a blood clotting factor, a zymogen (inactive enzyme precursor) of serine protease which plays an important role in the blood coagulation cascade. The FIX is activated in the presence of vitamin K. The activated FIX (FIXa) forms a complex with calcium ions, membrane phospholipids and coagulation Factor VIII to activate coagulation Factor X. This cascade results in the creation of platelets for blood clotting.