1. Childhood Cancer Research Unit; Department of Women's and Children's Health; Karolinska University Hospital and Karolinska Institutet; Stockholm Sweden
2. Department of Paediatrics; Aalborg University Hospital; Aalborg Denmark
3. Children's Hospital and Department of Haematology; Cancer Centre; Helsinki University Central Hospital; Helsinki Finland
4. Department of Paediatrics; Aarhus University Hospital; Aarhus Denmark
5. Departments of Paediatrics and Coagulation Disorders; University of Lund, University Hospital; Malmö Sweden
6. Department of Paediatric Haematology and Oncology; Skåne University Hospital; Malmö and Lund Sweden
7. Children's Hospital; Landspitali University Hospital; Reykjavík Iceland
8. Department of Haematology/Oncology; Tallinn Children's Hospital; Tallinn Estonia
9. Department of Paediatrics; Haukeland University Hospital; Bergen Norway
10. Centre for Paediatric Oncology and Haematology; Children's Hospital; Affiliate of Vilnius University Hospital Santariskiu Klinikos; Vilnius Lithuania
11. Department of Paediatrics and Adolescent Medicine; Copenhagen University Hospital, Rigshospitalet; Copenhagen Denmark
12. Department of Paediatric Medicine; Oslo University Hospital, Rikshospitalet; Oslo Norway