1. Clinic of Pediatric Hematology and Oncology, University Medical Centre Hamburg-Eppendorf, Hamburg, Germany;
2. Research Institute Children’s Cancer Centre, University Medical Centre Hamburg-Eppendorf, Hamburg, Germany
3. Department of Pediatric Hematology and Oncology, Medical School Hannover, Hannover, Germany;
4. Department of Pediatric Hematology and Oncology, Hospital Bielefeld, Bielefeld, Germany;
5. Department of Pediatric Hematology and Oncology, Hospital Bremen-Mitte, Bremen, Germany;
6. Department of Pediatric Oncology, Hematology and Clinical Immunology, University Medical Centre, Düsseldorf, Germany;
7. Department of Pediatric Hematology and Oncology, Helios Hospital, Krefeld, Germany;
8. Clinic of Pediatric Hematology and Oncology, University Medical Centre Leipzig, Leipzig, Germany;
9. Department of Pediatric Hematology/Oncology, University Hospital Mainz, Mainz, Germany;
10. Dr. von Hauner Children's Hospital, Ludwig Maximilians University, Munich, Germany;
11. Department of Pediatric Hematology and Oncology, Helios Hospital, Wiesbaden, Germany;