1. Division of Gastroenterology; Department of Medicine; University of Pennsylvania; Philadelphia, PA, USA
2. Abramson Cancer Center, University of Pennsylvania; Philadelphia, PA, USA
3. Department of Histopathology; Fox Chase Cancer Center; Philadelphia, PA, USA
4. Department of Pathology; Penn State Milton S. Hershey Medical Center; Hershey, PA, USA
5. Division of Gastroenterology and Hepatology; Mayo Clinic; Rochester, MN, USA
6. Department of Digestive and Liver Diseases; Irving Cancer Research Center; Columbia University Medical Center; New York, NY, USA
7. Department of Genetics; University of Pennsylvania; Philadelphia, PA, USA