Interaction of αFXII(a), plasminogen, polyp, and fibrin. Depiction of the potential template interactions among αFXII(a), plasminogen, and polyP on polymerized fibrin. Fibrin forms the initial network and acts as a template for both tPA- and FXIIa-mediated fibrinolysis due to its capacity to bind FXII(a), polyP, plasminogen, and tPA. PolyP binds to fibrin, αFXII(a), and plasminogen, potentially acting as an anchor to reinforce the association among these proteins. When αFXII(a) is bound to fibrin and polyP, its activation and plasminogen-activator activity is enhanced, facilitating plasmin generation on fibrin and subsequent degradation of the network. The cofactor capacity of fibrin in the stimulation of tPA-mediated plasminogen activation is well documented. Binding of the aFXIIa-polyP70 complex may to further facilitate plasminogen activation on the fibrin surface to accelerate fibrinolysis.