1. Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, Massachusetts 02115, United States
2. Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, United States
3. Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, California 91125, United States
4. Department of Systems Biology, Harvard Medical School, Boston, Massachusetts 02115, United States
5. Division of Engineering and Applied Science, California Institute of Technology, Pasadena, California 91125, United States