1. Department I of Internal Medicine, Center for Integrated Oncology Aachen Bonn Cologne and Duesseldorf, German CLL Study Group, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany;
2. Clinic for Hematology and Stem Cell Transplantation, West German Cancer Center, University Hospital Essen, University of Duisburg-Essen, Essen, Germany;
3. Outpatient Clinic, Landshut, Germany;
4. Department of Internal Medicine III, Ulm University, Ulm, Germany;
5. Study Centrum Unter Ems, Practice for Oncology and Hematology, Leer, Germany;
6. Practice for Oncology and Hematology, Erlangen, Germany;
7. Practice for Oncology and Hematology, Würzburg, Germany;
8. Medicinum, Hildesheim, Germany;
9. Department of Hematology, Brüder Krankenhaus, Paderborn, Germany;
10. Practice for Internal Medicine, Marburg, Germany;
11. Practice for Oncology and Hematology, Cologne, Germany;
12. Practice for Internal Medicine, Kronach, Germany; and
13. Department of Hematology, Oncology, Immunology, Palliative Care, Infectious Diseases and Tropical Medicine, Klinikum Schwabing, Munich, Germany