1. Department of Molecular Microbiology & Immunology, University of Southern California, Los Angeles, CA 90033 USA
2. Institute for Genetic Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033 USA
3. La Jolla Bioengineering Institute, San Diego, CA 9212
4. Department of Preventive Medicine, University of Southern California, Los Angeles, CA 90033 USA
5. Department of Molecular Biology & Biochemistry, University of Southern California, Los Angeles, CA 90033 USA