Male SKH-1 hairless mice (20 g each) were purchased from Central Lab. Animal Inc. (Seoul, Korea). The animals were kept in an air-conditioned room at 22±1◦C and 60±5% humidity under a 12 h light/12-h dark cycle with free access to food pellets and drinkingwater throughout the experiment. The ethical guidelines, described in the NIH Guide for Care and Use of Laboratory Animals, were followed throughout the experiments.