1. Department of Bioinformatics and Computational Biology, George Mason University, 10900 University Blvd., MSN 5B3, Manassas, Virginia 20110
2. Clinical Investigation Facility, David Grant USAF Medical Center, Travis, California 94535
3. Department of Ophthalmology, Howe Laboratory, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, Massachusetts 02114
4. State Key Laboratory for Molecular Virology and Genetic Engineering, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Nanwei Road 27, Xuanwu District, Beijing 100050, People's Republic of China