1. The National Children's Research Centre, Oncology Division, Gate 5; Our Lady's Children's Hospital; Crumlin Dublin 12 Ireland
2. Theodor-Boveri-Institute/Biocenter, Developmental Biochemistry, and Comprehensive Cancer Center Mainfranken; Wuerzburg University; 97074 Wuerzburg Germany
3. Department of Pediatric Oncology and Hematology; Saarland University Hospital; 66421 Homburg Germany
4. Princess Maxima Center for Pediatric Oncology/Hematology; Utrecht The Netherlands
5. Kiel Paediatric Cancer Registry; Christian Albrechts University; 24105 Kiel Germany
6. Histology Laboratory; Our Lady's Children's Hospital; Crumlin Dublin 12 Ireland
7. University of Dublin, Trinity College; Dublin 2 Ireland