1. Key State Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China.
2. Institute of Genetics and Developmental Biology, International College, University of Chinese Academy of Science (IC-UCAS), Beijing, China.
3. Department of General Surgery, The General Hospital of Chinese People's Armed Police Forces, Beijing, China.
4. Division of Medical Education, Brighton and Sussex Medical School, University of Brighton, Brighton, United Kingdom.