1. Department of Pathology and Laboratory Medicine (C.V.C), University of Pennsylvania, Philadelphia, Pennsylvania 19104
2. Lombardi Cancer Center (P.A.F.), Department of Oncology, Georgetown University, Washington, D.C. 20057
3. Channing Laboratories, Department of Medicine, Brigham and Women’s Hospital and Harvard Medical School, and Department of Epidemiology (S.E.H.), Harvard School of Public Health, Cambridge, Massachusetts 02115
4. Department of Comparative Bioscience (L.A.S.), University of Wisconsin, Madison, Wisconsin 53706