1. Department of Internal Medicine III, University Hospital of Ulm, Ulm;
2. Department of Medicine (Cancer Research), University Hospital of Essen, Essen;
3. Department of Hematology, Hemostasis and Oncology, Hannover Medical School, Hannover; and
4. Department of Hematology/Oncology, Medical Center, Otto-von-Guericke University of Magdeburg, Magdeburg, Germany