1. Department of Pediatrics and Adolescent Medicine; Aarhus University Hospital; Aarhus Denmark
2. Department of Hematology; Aarhus University Hospital; Aarhus Denmark
3. Institution for Clinical Sciences; Department of Pediatrics; Queen Silvia Children's Hospital; Gothenburg Sweden
4. Department of Pediatrics; Queen Mary Hospital and Hong Kong Pediatric Hematology and Oncology Study Group (HKPHOSG); Hong Kong China
5. Department of Pediatrics; Landspitali University Hospital; Reykjavik Iceland
6. Department of Pediatrics; VU University Medical Center Amsterdam, and Dutch Childhood Oncology Group; The Hague The Netherlands
7. Division of Hematology-Oncology and Stem Cell Transplantation; Children's Hospital; University of Helsinki; Helsinki Finland
8. Department of Pediatrics and Adolescent Medicine; Rigshospitalet; University of Copenhagen; Copenhagen Denmark
9. Department of Pediatrics; Ghent University Hospital; Ghent Belgium
10. Department of Woman´s and Children´s Health; Uppsala University; Uppsala Sweden
11. Division of Pediatric and Adolescent Medicine; Oslo University Hospital; Oslo Norway