1 Division of Gastroenterology and Hepatology, Key Laboratory of Gastroenterology and Hepatology, Ministry of Health, Renji Hospital, School of Medicine, Shanghai Jiao Tong University; Shanghai Institute of Digestive Disease, Shanghai 200001, China.
2 Division of Rheumatology, Allergy and Clinical Immunology, School of Medicine, University of California, Davis, CA 95616, USA.