1. Department of Pediatrics; Division of Hematology/Oncology; IWK Health Centre; Halifax Nova Scotia Canada
2. Department of Medicine; Washington University School of Medicine; St. Louis MO USA
3. Laboratory of Vascular Translational Science; U1148, Institut National de la Santé et de la Recherche Médicale (INSERM); Paris France
4. Division of Angiology and Hemostasis; Geneva University Hospitals and Faculty of Medicine; Geneva Switzerland
5. Department of Vascular Medicine and Department of Hematology; Academic Medical Center; Amsterdam the Netherlands