1Experimental Research Center for Infectious Diseases, Institute for Virus Research, Kyoto University, Sakyo-ku, Kyoto 606-8507, Japan;
2Center for Animal Resources and Development, Kumamoto University, Kumamoto, Kumamoto 860-0811, Japan;
3Center for Medical Genomics, National Cancer Center Research Institute, Chuo, Tokyo 104-0045, Japan;
4Laboratory of Systems Biology and Medicine, Research Center for Advanced Science and Technology, The University of Tokyo, Meguro, Tokyo 153-8904, Japan