1. Department of Pediatric Hematology and Oncology University Duisburg‐Essen, University Hospital Essen Essen Germany
2. Department of Pediatric Oncology and Hematology Charité ‐ Universitätsmedizin Berlin Berlin Germany
3. Amsterdam UMC Location VU University Medical Centre Amsterdam The Netherlands
4. Institut Curie PSL Research University and University of Paris Paris France
5. Gazi University School of Medicine Ankara Turkey
6. Filatov Eye Institute Odessa Odessa Ukraine
7. Department of Ophthalmology University Duisburg‐Essen, University Hospital Essen Essen Germany
8. Children's Hospital University of Tuebingen Tuebingen Germany
9. Pediatric Oncology, Sheba Medical Center Tel Aviv University Tel Aviv Israel
10. Centro Hospitalar e Universitário de Coimbra University of Coimbra Coimbra Portugal
11. Royal London Hospital and Great Ormond Street Hospital London England
12. Hospital Virgen Macarena Sevilla Spain
13. Ocular Oncology Siena University Hospital Siena Italy
14. University Hospital Brno and St. Anna University Hospital/ICRC Masaryk University Brno Czech Republic
15. East‐Tallinn Central Hospital Tallinn Estonia
16. Hacettepe University Hospital Ankara Turkey
17. Department of Ophthalmology Semmelweis University Budapest Hungary
18. Pediatric Hematology, Oncology and Stem Cell Transplant Division Padua University Hospital Padua Italy
19. Department of Pediatric Oncology and Hematology University Children's Hospital of Krakow Krakow Poland
20. Centre for Pediatric Oncology and Hematology Vilnius University Vilnius Lithuania
21. Department of Pediatric Hematology/Oncology IRCCS, Ospedale Pediatrico Bambino Gesù Rome Italy
22. The Children's Memorial Health Institute Warsaw Poland
23. Pediatric Hematology and Oncology University Hospital Vall d'Hebron Barcelona Spain
24. Hospital La Paz Madrid Spain
25. Charles University in Prague 2nd Faculty of Medicine and University Hospital Motol Prague Czech Republic
26. Department of Particle Therapy University Hospital Essen, West German Proton Therapy Centre Essen (WPE), West German Cancer Center (WTZ) Essen Germany
27. German Consortium for Translational Cancer Research (DKTK), Essen Germany German Cancer Research Center (DKFZ) Heidelberg Germany
28. The Goldschleger eye institute, Sheba Medical Center Tel Aviv University Tel Aviv Israel
29. Division of Pediatric Hematology/Oncology Medical University of Graz Graz Austria
30. Birmingham Children's Hospital Birmingham England
31. Department of Ophthalmology, Amsterdam UMC Vrije Universiteit Amsterdam, Cancer Center Amsterdam Amsterdam The Netherlands
32. Jules‐Gonin Eye Hospital, Fondation Asile des Aveugles University of Lausanne Lausanne Switzerland
33. Department of Pediatric Hematology and Oncology University Hospital CHUV University of Lausanne Lausanne Switzerland
34. Hospital Sant Joan de Deu Barcelona Spain