1. Department of Hematology; Herlev University Hospital; University of Copenhagen; Herlev; Denmark
2. Department of Clinical Sciences; Queen Silvia's Children's Hospital; Gothenburg; Sweden
3. Hematology Center Karolinska; Karolinska University Hospital Solna; Stockholm; Sweden
4. Hematology, Oncology and Transfusion Medicine Center; Vilnius University Hospital Santariskiu Klinikos; Vilnius University; Vilnius; Lithuania
5. Department of Hematology; Uppsala University Hospital; Uppsala; Sweden
6. Childhood Cancer Research Unit; Karolinska Institute; Astrid Lindgren's Childrens Hospital; Karolinska University Hospital; Stockholm; Sweden
7. Department of Hematology; Aarhus University Hospital; Aarhus C; Denmark
8. Department of Hematology and Coagulation; Sahlgrenska University Hospital; Gothenburg; Sweden
9. Department of Clinical Immunology; Section 7631; University Hospital Rigshospitalet; Copenhagen; Denmark
10. Children's Hospital; Landspitali University Hospital; Reykjavík; Iceland
11. Department of Hematology; Rigshospitalet; Copenhagen; Denmark
12. Department of Hematology; St. Olav's Hospital; Trondheim University Hospital; Trondheim; Norway
13. Department of Pediatrics; Helsinki University Central Hospital; Helsinki; Finland
14. Clinic of Childrens' Disease; Faculty of Medicine; Vilnius University; Vilnius; Lithuania
15. Division of Pediatric Hematology-Oncology; University of Tampere; Tampere; Finland
16. Department of Pediatrics; St. Olav's Hospital; Trondheim University Hospital; Trondheim; Norway
17. Department of Paediatrics and Adolescent Medicine, Rigshospitalet; Institute of Gynaecology, Obstetrics and Paediatrics; Faculty of Medicine; University of Copenhagen; Copenhagen; Denmark