1. Department of Health, Behavior and Society; Johns Hopkins Bloomberg School of Public Health; Baltimore; USA
2. Cancer Education Center, Samsung Comprehensive Cancer Center, Samsung Medical Center; Sungkyunkwan University School of Medicine; Seoul; Korea
3. Division of Cardiovascular & Genetic Diseases, Department of Biomedical Sciences; National Institute of Health; Seoul; Korea
4. Department of Thoracic Surgery, Samsung Medical Center; Sungkyunkwan University School of Medicine; Seoul; Korea