1 Division of Gastroenterology, Department of Medicine, Hospital of the University of Pennsylvania, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania.
2 Division of Gastroenterology, Department of Medicine, University of Michigan, Ann Arbor, Michigan.
3 Center for Esophageal Diseases and Swallowing, Division of Gastroenterology and Hepatology, Department of Medicine, University of North Carolina School of Medicine, Chapel Hill, North Carolina; Center for Gastrointestinal Biology and Disease, Division of Gastroenterology and Hepatology, Department of Medicine, University of North Carolina School of Medicine, Chapel Hill, North Carolina. Electronic address: edellon@med.unc.edu.