1. Department of Pediatric Hematology/Oncology; Hannover Medical School, Children's Hospital; Hannover Germany
2. Department of Pediatrics; St. Anna Children's Hospital and Children's Cancer Research Institute, Medical University of Vienna; Vienna Austria
3. Division for Pediatric Hematology and Oncology; Johann Wolfgang Goethe-University; Frankfurt Germany
4. Department of Pediatric Hematology/Oncology; University Medicine of the Johannes Gutenberg-University Mainz; Mainz Germany
5. Division of Pediatric Hematology/Oncology; University Medical Center; Freiburg Germany
6. Department of Pediatric Oncology/Hematology; Saarland University; Homburg Germany
7. Division of Pediatric Hematology, Oncology and Stem Cell Transplantation, Medical Faculty; RWTH Aachen University; Aachen Germany
8. Department of Pediatric Hematology and Oncology; University Children's Hospital Muenster; Muenster Germany
9. Department of Pediatric Hematology and Oncology, Dr. von Hauner Children`s Hospital; Ludwig-Maximilians-University Munich; Munich Germany
10. Department of Pediatric Oncology/Hematology; Charité University Medical Center Berlin; Berlin Germany
11. Department of Pediatric Hematology-Oncology; University of Duisburg-Essen; Essen Germany