VWF and arteriovenous hemangioma/malformation: Beyond the control of primary hemostasis, several studies have suggested that VWF regulates angiogenesis through multiple pathways,37 whereas VWF multimer defect promotes the appearance of angiodysplasia in the gastrointestinal tract and other arteriovenous malformations.38 VWF is also expressed abundantly in cerebral endothelial cells and could be involved in cerebral vessel remodelling.18 VWF also modifies and damages blood–brain barrier permeability in certain pathologic settings39 and might favor cerebral vessel wall rupture with consecutive microbleeds.24