1 Division of Digestive and Liver Diseases, Department of Medicine, Columbia University Irving Medical Cancer, New York, New York; Department of Medicine, Vagelos College of Physicians and Surgeons, New York, New York; Herbert Irving Comprehensive Cancer Center, Columbia University Medical Center, New York, New York. Electronic address: sr2712@cumc.columbia.edu.
2 Division of Digestive and Liver Diseases, Department of Medicine, Columbia University Irving Medical Cancer, New York, New York; Department of Medicine, Vagelos College of Physicians and Surgeons, New York, New York.
3 Division of Digestive and Liver Diseases, Department of Medicine, Columbia University Irving Medical Cancer, New York, New York; Department of Medicine, Vagelos College of Physicians and Surgeons, New York, New York; Herbert Irving Comprehensive Cancer Center, Columbia University Medical Center, New York, New York.
4 Gastroenterology Section, VA San Diego Healthcare System, San Diego, California; Division of Gastroenterology, University of California San Diego, San Diego, California.