1. Gastrointestinal Pathology Service; Massachusetts General Hospital and Harvard Medical School; Boston MA USA
2. Division of Anatomical Pathology; Queen Elizabeth II Health Sciences Centre; Dalhousie University; Halifax NS Canada
3. Department of Pathology and Laboratory Medicine; Veterans General Hospital-Taipei; Taipei Taiwan
4. Department of Pathology; National Yang-Ming University School of Medicine; Taipei Taiwan
5. Department of Pathology; Royal Victoria Hospital; Belfast UK
6. Gastrointestinal Unit; Massachusetts General Hospital; Harvard Medical School; Boston MA USA
7. Gastrointestinal Pathology Service; Brigham and Women's Hospital; Harvard Medical School; Boston MA USA