1. Department of Pediatric Hematology Emma Children's Hospital Amsterdam the Netherlands
2. Department of Vascular Medicine Academic Medical Center Amsterdam the Netherlands
3. Children's Hospital and Hematology, Comprehensive Cancer Center Helsinki University Hospital University of Helsinki Helsinki Finland
4. Coagulation Unit Hematology Center Karolinska University Hospital and Department of Medicine Karolinska Inisitutet Stockholm Sweden
5. Radboud University Nijmegen Medical Center Nijmegen the Netherlands
6. Catharina Hospital Eindhoven the Netherlands
7. University Hospital la Fe Valencia Spain
8. Department of Plasma Proteins Sanquin‐AMC Landsteiner Laboratory Amsterdam the Netherlands
9. Leiden University Hospital Leiden the Netherlands
10. Sanquin Research Leiden the Netherlands