1. BioCircuits Institute, University of California, San Diego, La Jolla, California 92093, United States
2. San Diego Center for Systems Biology, La Jolla, California 92093, United States
3. Molecular Biology Section, Division of Biological Sciences, University of California, San Diego, La Jolla, California 92093, United States
4. Department of Bioengineering, University of California, San Diego, La Jolla, California 92093, United States