1. Department of Pathology, Division of Hematopathology, University of Pittsburgh School of Medicine, Pittsburgh, PA
2. Institute of Pathology, Eberhard-Karls-University of Tübingen, Tübingen, Germany
3. Department of Dermatology, Leiden University Medical Center, Leiden, the Netherlands
4. Department of Pathology, University of Texas Health Science Center, San Antonio, TX