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, Oncology and Transfusion Medicine Center Vilnius University Hospital Santariskiu Klinikos; Vilnius Lithuania
4. Department of Hematology; Uppsala University Hospital; Uppsala Sweden
5. Childhood Cancer Research Unit; Karolinska Institute; Astrid Lindgren's Children's Hospital; Karolinska University Hospital; Stockholm Sweden
6. Children's Hospital; Landspitali University Hospital; Reykjavík Iceland
7. Department of Hematology; North Estonia Medical Centre; Tallinn Estonia
8. Kaie Pruunsild; Tallinn Children's Hospital; Tallinn Estonia
9. Department of Hematology; St. Olav's Hospital; Trondheim University Hospital; Trondheim Norway
10. Centre for Pediatric Oncology and Hematology; Children's Hospital; Affiliate of Vilnius University Hospital Santariskiu Klinikos; Vilnius Lithuania
11. Division of Hematology-Oncology and Stem Cell Transplantation; Hospital for Children and Adolescents; Helsinki University Central Hospital; Helsinki Finland
12. Department of Pediatrics; St. Olav's Hospital; Trondheim University Hospital; Trondheim Norway
13. Department of Pediatrics and Adolescent Medicine; Rigshospitalet; Copenhagen Denmark
14. Institute of Gynecology; Obstetrics and Pediatrics; Faculty of Medicine. University of Copenhagen; Copenhagen Denmark