Wah Yang1,2,3,4. 1. Department of Metabolic and Bariatric Surgery, The First Affiliated Hospital, Jinan University, Guangzhou, China. yangwah@qq.com. 2. Joint Institute of Metabolic Medicine Between State Key Laboratory of Pharmaceutical Biotechnology, The University of Hong Kong and Jinan University, Guangzhou, China. yangwah@qq.com. 3. State Key Laboratory of Pharmaceutical Biotechnology, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong, China. yangwah@qq.com. 4. Department of Medicine, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong, China. yangwah@qq.com.