1 Gastroenterology, Medicine, Sepulveda Ambulatory Care Center, Veterans Affairs Greater Los Angeles Healthcare System, North Hills, CA, USA (Felix W. Leung, Vivek Dixit, Nora Jamgotchian, Hui Jia).
2 Gastroenterology, Medicine, West Los Angeles Veterans Affairs Medical Center, Veterans Affairs Greater Los Angeles Healthcare System, West Los Angeles, CA, USA (Felix W. Leung, Vivek Dixit, Noam Jacob, James Sul).
3 University of California Los Angeles David Geffen School of Medicine, Los Angeles, CA, USA (Felix W. Leung, Vivek Dixit, Noam Jacob, Angshuman Saha, Holly Wilhalme).
5 Fourth Military Medical University, Xian, China (Long Chen, Hui Jia, Yanglin Pan, Linhui Zhang).
6 Veterans Affairs Palo Alto Health Care System, Palo Alto, CA, USA (Yu Chen, Ramsey Cheung, Shai Friedland, Jennifer Yi-Jiun Pan, Susan Y. Quan, Robert J. Wong).