1 Department I of Internal Medicine and German CLL Study Group, Center for Integrated Oncology Aachen Bonn Cologne Duesseldorf (CIO ABCD), University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany.
2 Department of Hematology and Stem Cell Transplantation, West German Cancer Center, University of Duisburg-Essen, Essen, Germany.
3 Department of Hematology, Cancer Center Amsterdam, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, Netherlands.
4 Department of Internal Medicine, Rijnstate Hospital, Arnhem, Netherlands.
5 Department of Hematology, Rigshospitalet, Copenhagen, Denmark.
6 Department of Internal Medicine III, Division of CLL, University Hospital Ulm, Ulm, Germany.