1. University of Cologne; Children's Hospital; Kerpener Str. 62 Cologne NW Germany 50937
2. University of Birmingham; Birmingham and Black Country NIHR CLAHRC; School of Health and population, Public Health Building College of Medical and Dental Sciences Birmingham West Midlands UK B15 2TT
3. Emma Children's Hospital/Academic Medical Center; Department of Paediatric Oncology; PO Box 22660 (room H4-139) Amsterdam Netherlands 1100 DD
4. Children's Hospital, University of Cologne; Pediatric Oncology and Hematology; Kerpener Strasse 62 Cologne Germany 50937