From the Children's Hospital of the J.W. Goethe University, Frankfurt; Charité, Pediatric Oncology/Hematology, Berlin; University Medical Center, Pediatric Oncology/Hematology, Düsseldorf; University Children's Hospital Tübingen, Tübingen; Medizinische Hochschule Hannover, Hannover; University Children's Hospital, Erlangen, Erlangen; University Children's Hospital Hamburg, Hamburg, Germany; and St Anna Kinderspital, Pediatric Oncology/Hematology, Vienna, Austria (At 2009-01-20)