1. Department of Internal Medicine, Affiliated Guangzhou Women and Children's Medical Center, Sun Yat‑sen University, Guangzhou, Guangdong 510080, P.R. China
2. Department of Biochemistry, Zhongshan School of Medicine, Sun Yat‑sen University, Guangzhou, Guangdong 510080, P.R. China
3. Department of Gastrointestinal Surgery, Traditional Chinese Medicine Hospital of Guangdong Province, Guangzhou, Guangdong 510080, P.R. China
4. Department of Laboratory Medicine, The Second Affiliated Hospital of South China University of Technology, Guangzhou, Guangdong 510080, P.R. China
5. Department of Physiology, University of Oklahoma, Health Sciences Center, Oklahoma City, OK 73104, USA