1. Princess Máxima Center for Pediatric Oncology; Utrecht The Netherlands
2. Department of Pediatric Oncology; Erasmus MC-Sophia Children's Hospital; Rotterdam The Netherlands
3. Department of Cellular Pathology; University Hospital of Wales/Cardiff, University School of Medicine; Heath Park Cardiff United Kingdom
4. Division of Oncology; Children's National Health System; Washington District of Columbia
5. Department of Pathology; Hopitaux Universitaires Est Parisien; Trousseau La Roche-Guyon Paris France
6. Department of Emergency Medicine; Medical University of Wroclaw; Wroclaw Poland
7. Cancer Section; University College London Institute of Child Health; London United Kingdom
8. Department of Pediatric Hematology and Oncology; Saarland University; Saarbrucken Germany