1. Wound Healing and Cell Biology Laboratory, Institute of Basic Medical Science, Trauma Center of Postgraduate Medical School, Chinese PLA General Hospital, 28 Fu Xing Road, Beijing 100853, P. R. China
2. Key Research Laboratory of Tissue Repair and Regeneration of PLA, and Beijing Key Research Laboratory of Skin Injury, Repair and Regeneration, First Affiliated Hospital to the Chinese PLA General Hospital, 51 Fu Cheng Road, Beijing 100048, P.R. China