It's the beginning of that final common pathway. So we see that antithrombin three is a glycoprotein that resembles the structure of alpha one antitrypsin. Now it binds with very high affinity to thrombin and it activates its activity and it also blocks it forms complexes with other factors of the intrinsic pathway and the final common pathway. So we have factor twelve, we have factor eleven and we have factor nine that are part of the intrinsic pathway and then we have the factor ten which is basically the initiation of the final common pathway. It's that factor that is part of that converging point between the intrinsic and the extrinsic pathway. Now let's move on to heparin and heparin cofactor two.