1. Department of Gastroenterology Beijing Friendship Hospital Capital Medical University National Clinical Research Center for Digestive Diseases Beijing Digestive Disease Center Beijing Key Laboratory for Precancerous Lesion of Digestive Disease Beijing 100050 P. R. China
2. Department of Urology Peking University Third Hospital Beijing 100191 P. R. China
3. Key Laboratory of Bio‐inspired Materials and Interfacial Science CAS Center for Excellence in Nanoscience Technical Institute of Physics and Chemistry Chinese Academy of Sciences Beijing 100190 P. R. China
4. University of Chinese Academy of Sciences Beijing 100049 P. R. China
5. Echo Biotech Co., Ltd. Beijing 102206 P. R. China