1. Neuroendocrine Unit, Massachusetts General Hospital, Boston, Massachusetts
2. Harvard Medical School, Boston, Massachusetts
3. Division of Gastroenterology, Massachusetts General Hospital, Boston, Massachusetts
4. Division of Pulmonology and Critical Care Medicine, Massachusetts General Hospital, Boston, Massachusetts
5. Clinical Pathology, Massachusetts General Hospital, Boston, Massachusetts
6. Endocrinology, Quest Diagnostics Nichols Institute, San Juan Capistrano, California