1. Department of Pediatric Oncology/Hematology, Erasmus Medical Center, Sophia Children's Hospital, Rotterdam, The Netherlands
2. Department of Clinical Genetics, Erasmus Medical Center, Rotterdam, The Netherlands
3. Dutch Childhood Oncology Group (DCOG), The Hague, The Netherlands
4. Department of Human Genetics, Radboud University Medical Center and Radboud Institute for Molecular Life Sciences, Nijmegen, The Netherlands
5. German Cooperative Study Group for Childhood Acute Lymphoblastic Leukemia (COALL), Hamburg, Germany
6. Department of Immunology, Erasmus Medical Center, Rotterdam, The Netherlands
7. Sanquin Research and Landsteiner Laboratory, Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands
8. Princess Máxima Center for Pediatric Oncology, Utrecht, The Netherlands