1. Immunology Unit, Department of Microbiology, Faculty of Medicine, Chiang Mai University, Chiang Mai 50200, Thailand
2. Division of Gastroenterology and Hepatology, Stanford University School of Medicine, Stanford, CA 94305, USA
3. Division of Gastroenterology and Hepatology, Department of Medicine, University of Arizona College of Medicine, Phoenix, AZ 85004, USA
4. Department of Internal Medicine, Banner University Medical Center, Phoenix, AZ 85006, USA