1. Department of Life Sciences, Pohang University of Science and Technology, Pohang, Gyeongbuk 790-784, South Korea.
2. Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA.
3. Medical Genomics Research Center, KRIBB, Daejeon, South Korea.
4. Department of Functional Genomics, University of Science and Technology, Daejeon, South Korea.