Guo-You Zhang1, Tian Liao2, Xiao-Bing Fu3, Qing-Feng Li4. 1. Department of Plastic and Reconstructive Surgery, Shanghai Ninth People's Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China. 2. Department of Head and Neck Surgery, Fudan University Shanghai Cancer Center, Shanghai, China. 3. Wound Healing and Cell Biology Laboratory, Institute of Basic Medical Science, First Hospital Affiliated to the PLA General Hospital, Beijing, China. 4. Department of Plastic and Reconstructive Surgery, Shanghai Ninth People's Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China. Electronic address: dr.liqingfeng@yahoo.com.