1. Pediatric Hematology/Oncology, Department of Pediatrics University Hospital Tuebingen Tubingen Germany
2. Swabian Children's Cancer Center Children's Hospital, Klinikum Augsburg Augsburg Germany
3. Pediatrics III, West German Cancer Centre Essen German Cancer Consortium (DKTK) site Essen, National Center for Tumordiseases (NCT) site Essen University Hospital Essen Essen Germany
4. Pediatric Haematology/Oncology/Immunology, Department of Pediatrics University Hospital Rostock Rostock Germany
5. Pediatric Oncology Otto‐von‐Guericke‐University Magdeburg Germany
6. Department of Internal Medicine VIII Medical Oncology and Pneumology University of Tuebingen Tuebingen Germany
7. German Cancer Consortium (DKTK), German Cancer Research Center (DKFZ), Partner Site Tuebingen Tuebingen Germany
8. Department of Pediatric Hematology and Oncology Hannover Medical School Hannover Germany
9. Clinic of Pediatrics Dortmund Municipal Hospital Dortmund Germany