1. Department of Pediatric Solid Tumors Princess Máxima Center for Pediatric Oncology Utrecht The Netherlands
2. Institut Curie, SIREDO Oncology Center (Care, Innovation and Research for Children and AYA with Cancer) PSL Research University Paris France
3. Department of Paediatric Oncology Royal Manchester Children's Hospital Manchester UK
4. Department of Pathology Royal Manchester Children's Hospital Manchester UK
5. Paediatric Hematology and Oncology Division Padova University Padova Italy
6. Department of EpSSG Sarcoma EpSSG Data Centre Istituto Oncologico Veneto IRCCS Padova Italy
7. Department of Oncology University College London Hospitals NHS Foundation Trust London UK
8. Department of Paediatric Surgery Royal Manchester Children's Hospital Manchester UK
9. Radiology Department Great Ormond Street Hospital for Children London UK
10. Department of Paediatric CHC‐Clinique Esperance Montegnée Belgium
11. Department of Pathology Fondazione IRCCS Istituto Nazionale dei Tumori Milan Italy
12. Department of Paediatric Oncology Fondazione IRCCS Istituto Nazionale Tumori Milan Italy