1. Gastroenterology; Duke University; Durham NC USA
2. Duke Clinical Research Institute; Durham NC USA
3. Section on Gastroenterology & Hepatology; Wake Forest University School of Medicine; Winston-Salem NC USA
4. University of North Carolina; Chapel Hill NC USA
5. Gastroenterology; Brody School of Medicine; East Carolina University; Greenville NC USA
6. Gastroenterology; University of Michigan Medical Center; Ann Arbor MI USA
7. Laboratory of Pathology; National Cancer Institute; Bethesda MD USA