1. Department of Leukemia, University of Texas M. D. Anderson Cancer Center, Houston, TX;
2. Institute of Pathology, University of Würzburg, Würzburg, Germany;
3. Chronic Lymphocytic Leukemia Research Consortium, and Division of Hematology/Oncology, Department of Medicine, University of California San Diego, San Diego, CA;
4. Department of Biostatistics, University of Texas M. D. Anderson Cancer Center, Houston, TX; and
5. Department of Biostatistics and Computational Biology, Dana-Farber Cancer Institute, Boston, MA