Erratum: All-Trans Retinoic Acid Attenuates Ultraviolet Radiation-Induced Down-Regulation of Aquaporin-3 and Water Permeability in Human Keratinocytes by Cong Cao, Shu Wan, Qin Jiang, Ashley Amaral, Shan Lu, Gang Hu, Zhigang Bi, Nicola Kouttab, Wenming Chu and Yinsheng Wan