1. Princess Máxima Center for Pediatric Oncology Utrecht The Netherlands
2. NHL‐BFM Study Center and Pediatric Hematology and Oncology University Hospital Muenster Münster Germany
3. Department of Pediatric Hematology and Oncology St. Anna Children's Hospital Medical University of Vienna Vienna Austria
4. St. Anna Children's Cancer Research Institute Vienna Austria
5. Division of Pediatric Hematology‐Oncology Istanbul University Oncology Institute Istanbul Turkey
6. Department of Radiology and Nuclear Medicine University Medical Center Utrecht Utrecht The Netherlands
7. Department of Genetics University Medical Center Utrecht Utrecht The Netherlands
8. Erasmus Medical Center Sophia Children's Hospital Rotterdam The Netherlands