1. Department of Pediatrics, Christian-Albrechts-University Kiel and University Medical Center Schleswig-Holstein, Kiel, Germany;
2. Division of Pediatric Hematology and Oncology, Hannover Medical School, Hannover, Germany;
3. Medical Statistics Unit, Department of Clinical Medicine and Prevention, University of Milano-Bicocca, Monza, Italy;
4. Department of Pediatrics, University of Milano-Bicocca, Ospedale S. Gerardo, Monza, Italy;
5. Centro M. Tettamanti, Clinica Pediatrica Università Milano-Bicocca, Monza, Italy;
6. Department of Pediatrics, St. Anna Children’s Cancer Research Institute and St. Anna Children’s Hospital, Medical University School, Vienna, Austria;
7. Department of Pediatric Hemato-Oncology, Ospedale Bambin Gesù, Rome, University of Pavia, Pavia, Italy;
8. Department of Pediatric Oncology, University Children’s Hospital, Zürich, Switzerland;
9. Direzione Generale, Azienda Sanitaria Provinciale, Ragusa, Italy;
10. Institute of Human Genetics, Ruprecht-Karls-University, Heidelberg, Germany;
11. Department of Pediatric Hematology and Oncology, University Hospital, Essen, Germany;
12. Pediatric Hemato-Oncology, Department of Women's and Children's Health, University of Padova, Padova, Italy;
13. Hematology/Oncology, Robert-Rössle-Klinik at the HELIOS Klinikum, Charité, Berlin, Germany;
14. Department of Pediatric Oncology, Hematology and Immunology, University of Heidelberg, Heidelberg, Germany;
15. Department of Pediatric Hemato-Oncology, Azienda Policlinico–Ospedale Vittorio Emanuele, Catania, Italy;
16. Children’s Hospital of Eastern Switzerland, St. Gallen, Switzerland;
17. Department of Pediatric Hematology and Oncology, Santobono-Pausilipon Hospital, Napoli, Italy;
18. Pediatric Hematology and Oncology, Justus-Liebig University, Gießen, Germany;
19. Pediatric Hematology and Oncology, Charité Medical Center, Humboldt University, Berlin, Germany;
20. Department of Pediatric Hemato-Oncology, Regina Margherita Children’s Hospital, Torino, Italy; and
21. Department of Pediatric Hematology and Oncology, University Children’s Hospital, Münster, Germany