Department of General Surgery, Xinqiao Hospital, Third Military Medical University, Chongqing 400037, China. xqzheng@shnu.edu.cn.|Department of General Surgery, Xinqiao Hospital, Third Military Medical University, Chongqing 400037, China. xqzheng@shnu.edu.cn.|Department of General Surgery, Xinqiao Hospital, Third Military Medical University, Chongqing 400037, China. xqzheng@shnu.edu.cn.|Department of General Surgery, Xinqiao Hospital, Third Military Medical University, Chongqing 400037, China. xqzheng@shnu.edu.cn.|Division of Biology and Biological Engineering, California Institute of Technology, 1200 East California Blvd, Pasadena, CA 91125, USA. woldb@caltech.edu.