Affiliation: | 1. Department of Pediatrics and Adolescent Medicine, University Hospital, Rigshospitalet, Copenhagen, Denmark;2. Section of Biostatistics, Department of Public Health, University of Copenhagen, Copenhagen, Denmark;3. Institute of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark;4. Department of Pediatrics, Institution for Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden;5. Department of Pediatrics, St Olavs Hospital, Trondheim, Norway;6. Department of Laboratory Medicine, Children''s and Women''s Health, Faculty of Medicine, Norwegian University of Science and Technology, Trondheim, Norway;7. Children''s Hospital, Helsinki University Central Hospital and University of Helsinki, Helsinki, Finland;8. Pediatric Hematology-Oncology, Barnaspitali Hringsins, Landspitali University Hospital, Reykjavik, Iceland;9. Centre for Paediatric Oncology and Haematology, University Children''s Hospital, Vilnius, Lithuania;10. Department of Oncology and Haematology, Tallinn Children''s Hospital, Tallinn, Estonia |