1. Great Ormond Street Hospital for Children, London, United Kingdom;
2. European Society for Blood and Marrow Transplantation (EBMT) Data Office Leiden, Leiden, The Netherlands;
3. Julius Center for Health Sciences and Primary Care, University Medical Center (UMC) Utrecht, Utrecht University, Utrecht, The Netherlands;
4. Unité d’Immunologie et d’Hématologie, Hôpital Necker, Paris, France;
5. Department of Pediatrics and Adolescent Medicine, University Medical Center Ulm, Ulm, Germany;
6. Dr. von Hauner Children's Hospital, University Hospital, Ludwig-Maximilians-Universität München, Munich, Germany;
7. Pediatric Hematology/Oncology, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia;
8. Department of Clinical Immunology and Transplantation, Jagiellonian University Medical College, Transplantation Center, University Children’s Hospital, Krakow, Poland;
9. Centre for Allogeneic Stem Cell Transplantation, Karolinska University Hospital Huddinge, Stockholm, Sweden;
10. Department of Pediatrics, UMC Utrecht, University Utrecht, Utrecht, The Netherlands;
11. Princess Maxima Center, Utrecht, The Netherlands;
12. Instituto da Criança, Hospital das Clínicas da Universidade de São Paulo, São Paulo, Brazil;
13. Hospital Israelita Albert Einstein, São Paulo, Brazil;
14. Division of Pediatric Hematology and Oncology Medical Center, Department of Pediatric Hematology/Oncology and BMT, Wroclaw Medical University, Wroclaw, Poland;
15. Department of Pediatrics and Adolescent Medicine, Faculty of Medicine, University of Freiburg, Freiburg, Germany;
16. Clinic of Hematology, University Hospital, Zurich, Switzerland;
17. Department of Paediatric Hematology and Oncology, University Hospital Motol, Prague, Czech Republic;
18. Department Pediatric Hematology/Oncology, Hannover Medical University, Hannover, Germany;
19. Pediatric BMT Centre, Ege University, Izmir, Turkey;
20. Istituto di Ricovero e Cura a Carattere Scientifico (IRRCS), Ospedale Pediatrico Bambino Gesù, Rome, Italy;
21. Department of Bone Marrow Transplantation, Hadassah University Hospital, Jerusalem, Israel;
22. Bone Marrow Unit, Department of Paediatric Hematology, Central Manchester National Health Service (NHS) Trust, Manchester, United Kingdom;
23. Department of Paediatric Immunology, Great North Children’s Hospital, Newcastle upon Tyne, United Kingdom;
24. Willem-Alexander Kinderziekenhuis, Leiden University Medical Center, Leiden, The Netherlands;
25. Pediatric Hematology-Oncology, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy;
26. Oncohematology and Bone Marrow Transplantation (BMT) Unit, Ospedale dei Bambini, Brescia, Italy;
27. Division of Pediatric Hematology, Oncology, and Stem Cell Transplantation, Helsinki University Hospital, Helsinki, Finland;
28. Department of Hematology, Royal Hospital for Children, Glasgow, United Kingdom;
29. Children's Cancer Research Institute, St Anna Children’s Hospital, Vienna, Austria;
30. División of Pediatric Hematology and Oncology, Department of Pediatrics, Erciyes University, Kayseri, Turkey;
31. Division of Stem Cell Transplantation, University Children’s Hospital, Eleonore Foundation, Zurich, Switzerland;
32. Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, United Kingdom; and
33. Department of Hematopoietic Stem Cell Transplantation, Dmitry Rogachev National Medical Center of Pediatric Hematology, Oncology and Immunology, Moscow, Russia