Dr. Jerry Avorn is Professor of Medicine at Harvard Medical School and Chief of the Division of Pharmacoepidemiology and Pharmacoeconomics at Brigham and Women's Hospital, both in Boston. Stephen Morrissey, the interviewer, is the Managing Editor of the Journal. Supplement to: Avorn J. Learning about the Safety of Drugs - A Half-Century of Evolution. N Engl J Med 2011;365:2151-3.