Department of Dermatology, the Third Xiangya Hospital, Central South University, Changsha, Hunan 410013, China. Department of Laboratory, the Third Xiangya Hospital, Central South University, Changsha, Hunan 410013, China. Department of Cell Biology and Anatomy, University of South Carolina School of Medicine, Columbia, SC 29209, USA. Department of Dermatology, the Third Xiangya Hospital, Central South University, Changsha, Hunan 410013, China. Electronic address: xiaoyun3@csu.edu.cn.