It is constantly active, but its adhesion to these factors is increased by the presence of heparan sulfate (a glycosaminoglycan) or the administration of heparins (different heparinoids increase affinity to FXa, thrombin, or both).
Está constantemente activa, pero a súa adhesión a estes factores vese incrementada pola presenza de heparán sulfato (un glicosaminoglicano) ou a administración de heparinas (diferentes heparinoides incrementan a afinidade ao FXa, á trombina, ou a ambos os dous).