1. Center for Thrombosis and Hemostasis and
2. Department of Pharmacology, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany;
3. Division of Epidemiology, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX; and
4. Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA