1. From the Department of Hematology, University of Freiburg Medical Center, Freiburg, Germany; the Department of Hematology, Leyenburg Hospital, The Hague, The Netherlands; the Institute of Cancer Biology, Danish Cancer Society, Copenhagen, Denmark; the Departments of Pathology, University of Freiburg, Germany, and the University Hospital of Münster, Germany; and the Norris Cancer Center, University of Southern California, Los Angeles.