1. Department of Pediatrics and Adolescent Medicine, Division of Pediatric Hematology and Oncology, Medical Center, Faculty of Medicine University of Freiburg Freiburg Germany
2. Department of Paediatric Haematology and Oncology, Second Faculty of Medicine Charles University and University Hospital Motol Prague Czech Republic
3. Dept. of Pediatric Hematology and Stem Cell Transplantation Central Hospital of Southern Pest ‐ National Institute of Hematology and Infectious Diseases Budapest Hungary
4. National Children's Cancer Service Children's Health Ireland Dublin Ireland
5. Department of Pediatric Hematology and Oncology IRCCS Ospedale Pediatrico Bambino Gesù, Catholic University of the Sacred Hearth Rome Italy
6. Department of Pediatric Hematology and Oncology Oslo University Hospital Oslo Norway
7. Bone Marrow Transplantation Unit Detská fakultná nemocnica s poliklinikou v Bratislave Bratislava Slovakia
8. Hematology and Hemotherapy Unit Hospital Infantil Universitario Niño Jesús Madrid Spain
9. Department of Hematology, Oncology and Stemcell Transplantation University Children's Hospital Zurich Switzerland
10. Department of Stem Cell Transplantation Princess Máxima Center for Pediatric Oncology and Wilhelmina Children's Hospital Utrecht The Netherlands
11. Pediatric Hematopoietic Stem Cell Transplantation and Immunodeficiency, The Child and Adolescent Department, Rigshospitalet Copenhagen University Hospital Copenhagen Denmark
12. St. Anna Children's Hospital, Department of Pediatrics Medical University of Vienna, and St. Anna Children's Cancer Research Institute (CCRI) Vienna Austria
13. Department of Pediatric Hematology and Oncology University Hospital Leuven Gasthuisberg Leuven Belgium
14. Department of Paediatric Transplantology, Haematology and Oncology Warsaw Medical University Warsaw Poland
15. Division of Hematology‐Oncology and SCT Children's Hospital University of Helsinki and Helsinki University Hospital Helsinki Finland
16. Department of Pediatric Hematology Oncology (T.A.O.) Aghia Sophia Children's Hospital Athens Greece
17. Pediatric Hematology Unit, Hospital Dona Estefânia Centro Hospitalar Universitário de Lisboa Central Lisbon Portugal
18. Unit of Oncology and Haematology, University Children's Hospital Ljubljana University Medical Centre Ljubljana Slovenia