1. Department of Hematology and Oncology; University Hospital Mannheim; Mannheim Germany
2. Department of Pathology; Ludwig Maximilians University; Munich Germany
3. Department of Pathology; University Hospital Mannheim; Mannheim Germany
4. MLL, Munich Leukemia Laboratory; Munich Germany
5. Wessex Regional Genetics Laboratory; University of Southampton, Salisbury District Hospital; Salisbury United Kingdom
6. Faculty of Medicine; University of Southampton; Southampton United Kingdom