<unk>  or plasma thromboplastin antecedent is the zymogen form of<unk> a, one of the enzymes of the coagulation cascade. Like many other coagulation factors, it is a serine protease. In humans,<unk>  is encoded by the F11 gene.
Factor XI
Factor VIII
Factor VIII 
Factor IX
Thrombin
Prothrombinase
Von Willebrand factor
Fibrinogen