Von Willebrand factor (vWF) is a blood glycoprotein involved in hemostasis.
It is a highly adhesive procoagulant molecule that mediates platelet adhesion to endothelial and subendothelial surfaces.
It is deficient or defective in von Willebrand disease and is involved in a large number of other diseases, including thrombotic thrombocytopenic purpura, Heyde's syndrome, and possibly hemolytic-uremic syndrome.
Increased plasma levels in a large number of cardiovascular, neoplastic, and connective tissue diseases are presumed to arise from adverse changes to the endothelium, and may contribute to an increased risk of thrombosis.