1. Department of Paediatrics, Division of Oncology-Haematology, VU University Medical Center, PO Box 7057, 1000 MB Amsterdam, The Netherlands
2. Department of Obstetrics and Gynaecology, VU University Medical Center, PO Box 7057, 1000 MB Amsterdam, The Netherlands
3. Princess Máxima Center for Paediatric Oncology, Lundlaan 6, 3584 EA Utrecht, The Netherlands
4. Department of Paediatric Oncology/Haematology, Sophia Childrens’ Hospital/Erasmus MC-University Medical Center, Wytemaweg 40, 3015 GJ Rotterdam, The Netherlands
5. Department of Paediatric Oncology/Haematology, University of Groningen, University Medical Center Groningen, PO Box 3001, 9700 RB Groningen, The Netherlands
6. Department of Paediatric Oncology, Emma Children’s Hospital/Amsterdam Medical Center, PO Box 22660, 1100 DD Amsterdam, The Netherlands
7. Department of Haematology, Radboud University, Nijmegen Medical Center, PO Box 9101, 6500 HB Nijmegen, The Netherlands
8. Department of Paediatric Oncology, Wilhelmina Children’s Hospital/University Medical Center Utrecht, PO Box 85090, 3508 AB Utrecht, The Netherlands
9. Willem-Alexander Children’s Hospital/Leiden University Medical Center, PO Box 9600, 2300 RC Leiden, The Netherlands
10. Department of Epidemiology, Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX Amsterdam, The Netherlands