Thrombomodulin is a specific endothelial cell receptor that forms a 1:1 stoichiometric complex with thrombin. This complex is responsible for the conversion of protein C to the activated protein C (protein Ca). Once evolved, protein Ca scissions the activated cofactors of the coagulation mechanism, factor Va and factor VIIIa, and thereby reduces the amount of thrombin generated. Defects in thrombomodulin are the cause of thrombophilia due to thrombomodulin defect (THR-THBDD). THR-THBDD is a hemostatic disorder characterized by a tendency to thrombosis.