1. Department of Pediatrics and Adolescent MedicineAarhus University Hospital Aarhus Denmark
2. Department of HematologyAarhus University Hospital Aarhus Denmark
3. Institution for Clinical SciencesDepartment of PediatricsQueen Silvia Children's Hospital Gothenburg Sweden
4. Department of PediatricsQueen Mary Hospital and Hong Kong Pediatric Hematology and Oncology Study Group (HKPHOSG) Hong Kong China
5. Department of PediatricsLandspitali University Hospital Reykjavik Iceland
6. Department of PediatricsVU University Medical Center Amsterdam The Netherlands
7. Princess Máxima Center for Pediatric Oncology Utrecht The Netherlands
8. Dutch Childhood Oncology Group The Hague The Netherlands
9. Division of Hematology‐Oncology and Stem Cell TransplantationNew Children's Hospital, University of Helsinki and Helsinki University Hospital Helsinki Finland
10. Department of Pediatrics and Adolescent MedicineRigshospitaletUniversity of Copenhagen Copenhagen Denmark
11. Department of Pediatric Hematology‐Oncology and Stem Cell TransplantationGhent University Hospital Ghent Belgium
12. Department of Woman´s and Children´s HealthUppsala University Uppsala Sweden
13. Division of Pediatric and Adolescent MedicineOslo University Hospital Oslo Norway