Consultant and professor of laboratory medicine and pathology, Mayo Clinic College of Medicine. Gastrointestinal and liver pathologist.  Graduated from National Taiwan University College of Medicine in 1985, and Master of Science in Pathology in 1987. He had his PhD degree in pathology from University of Pennsylvania in 1991. Had pathology residency training at University of Pittsburgh in 1991-1995 and gastrointestinal pathology fellowship at Johns Hopkins University in 1995-1997. He had worked as GI/liver pathologist and lecturer and assistant professor at Johns Hopkins University between 1997 and 2001, assistant and associate professor at MD Anderson cancer Center between 2001 and 2006, professor in 2007 to present at Mayo Clinic and as working group head of GI/liver pathology since 2009.  He has been co-principal investigator in multiple research grants and principal investigator for several clinical trials. His research focus is on Barrett's esophagus and esophageal cancer and celiac disease and has published more than 200 papers.