Impact of Von Willebrand Factor and Its Multimers on Angiogenesis

Inclusion Criteria: For patients: * Patient with von Willebrand disease proven by genetic analysis of the VWF gene. * Lack of treatment that could interfere with angiogenesis. * Patient informed by an information note sent to his home, with the possibility of objecting to the use of his blood samples in the context of research. For the control: * Patient with a normal coagulation report * Absence of abnormal hemorrhagic symptoms * Lack of notion of angiodysplasia. * Lack of treatment that could interfere with angiogenesis. * Patient informed by an information note sent to his home, with the possibility of objecting to the use of his blood samples in the context of research. Exclusion Criteria: * Patient under guardianship or curatorship. * Pregnant and lactating women. * Blood transfusion or treatment with von Willebrand factor concentrates less than 7 days old. * Treatment which may interfere with angiogenesis.