By Richard N. Mitchell, MD, PhD, Associate Professor of Pathology, Harvard Medical School, Boston, MA; Vinay Kumar, MBBS, MD, FRCPath, Professor and Chairman, Department of Pathology, University of Chicago, Pritzker School of Medicine, Chicago, IL; Abul K. Abbas, MBBS, Professor and Chair, Department of Pathology, University of California San Francisco School of Medicine, San Francisco, CA; and Nelson Fausto, MD, Chairman, Department of Pathology University School of Medicine, Seattle, WA |