1. Department of Pediatric Oncology and Hematology University of Cologne Cologne Germany
2. Department of Experimental Pediatric Oncology University of Cologne Cologne Germany
3. Center for Molecular Medicine, Medical Faculty University of Cologne Cologne Germany
4. Department of Pediatric Oncology and Hematology University of Leipzig Leipzig Germany
5. Swabian Children's Cancer Center, Children's Hospital University Hospital Augsburg Augsburg Germany
6. Department of Children and Adolescents, University Hospital Goethe University Frankfurt (Main) Frankfurt Germany
7. Department of Pediatric Oncology and Hematology University of Munster Munster Germany
8. Department of Pediatric Oncology and Hematology Olgahospital Stuttgart Stuttgart Germany
9. Department of Pediatric Hematology and Oncology and Hematology, Dr. von Hauner Children's Hospital Ludwig‐Maximilians‐University Munich Munich Germany
10. Institute of Medical Statistics and Computational Biology University of Cologne Cologne Germany