1. Department of Pediatric Hematology and Oncology; Children's Hospital; Hannover Medical School; Hannover Germany
2. Department of Pediatrics; St. Anna Children's Hospital and Children's Cancer Research Institute; Medical University of Vienna; Vienna Austria
3. Department of Pediatric Hematology-Oncology; University of Duisburg-Essen; Essen Germany
4. Department of Pediatric Hematology and Oncology; Charles University Prague; Czech Pediatric Hematology Working Group (CPH); Prague Czech Republic
5. Department of Pediatric Hematology/Oncology; University of Zurich; Zurich Switzerland
6. Department of Pediatrics; Aarhus University Hospital Skejby; Aarhus Denmark
7. Department of Pediatrics; Institution of Clinical Sciences; Sahlgrenska University Hospital; Gothenburg Sweden
8. Pediatric Oncology; VU University Medical Center; Amsterdam The Netherlands
9. Dutch Childhood Oncology Group (DCOG); The Hague The Netherlands
10. Princess Maxima Center for Pediatric Oncology; Utrecht The Netherlands
11. Department of Pediatric Hematology-Oncology and Stem Cell Transplantation; Ghent University Hospital; Ghent Belgium
12. Department of Pediatric Hematology and Oncology; IRCCS Ospedale Pediatrico Bambino Gesù; University of Pavia; Rome Italy
13. Oncologia ed Ematologia Pediatrica “Lalla Seràgnoli” Ospedale Sant'Orsola Malpighi Università di Bologna; Bologna Italy