1. From the Clinical Cooperation Unit Neuropathology, Division of Molecular Genetics, and Division of Biostatistics, German Cancer Research Center; Departments of Neuropathology and Pediatric Oncology, Hematology, and Immunology, University of Heidelberg, Heidelberg; Department of Neuropathology, Heinrich-Heine-University, Düsseldorf; Department of Pediatric Hematology and Oncology, University Medical Center Hamburg-Eppendorf; Cnopf'sche Kinderklinik, Nürnberg Children's Hospital, Nürnberg, Germany; and NN...