1. Department of Pediatrics, Samcheok-si Public Health Center, Samcheok, South Korea
2. Department of Pediatrics, Ajou University School of Medicine, Suwon, South Korea
3. Department of Bioinformatics, Department of Radiation Oncology, Ajou University School of Medicine, Suwon, South Korea
4. Department of Pediatrics, Inje University College of Medicine, Ilsan Paik Hospital, Goyang, South Korea