3 Comprehensive Cancer Center Mainfranken, Wuerzburg University, Wuerzburg, Germany.
4 Princess Maxima Centre for Pediatric Oncology, Utrecht, Netherlands.
5 Department of Diagnostic Pathology and Laboratory Medicine, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy.
6 Sorbonne Université, Department of Pathology, Hopitaux Universitaires Est Parisien, Paris, France.
7 Department of Pathology, Oslo University Hospital, Rikshospitalet, Oslo, Norway.
8 Molecular Bases of Genetic Risk and Genetic Testing Unit, Department of Preventive and Predictive Medicine, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy.
9 Great Ormond Street Institute of Child Health, University College London, London, UK.
10 Kiel Paediatric Tumour Registry, Department of Paediatric Pathology, University Hospital of Kiel, Kiel, Germany.
11 Department of Paediatric Oncology & Haematology, Saarland University, Homburg, Germany.