Protein C in the presence of Thrombin and Thrombomodulin is converted to Activated Protein C. APC is a natural anticoagulant that dampens coagulation by inactivating FVIIIa and FVa (cofactors for the tenase and prothrombinase complexes, respectively). The slide show entitled Activation of Protein C by Thrombin shows the relationship amongst these components.
