Hye Jin Yoo, Ji A. Seo, Sin Gon Kim, Kyung Mook Choi, Sei Hyun Baik, Dong Seop Choi and Chol Shin of Korea University College of Medicine in Ansan, Korea; Chang-Ho Yun of Seoul National University Bundang Hospital in Seongnam, Korea; and Sooyeon Suh of Sungshin Womens University in Seoul, Korea.