1. Department of Systems and Computational Biology, Albert Einstein College of Medicine, New York City, New York, USA
2. Department of Biology, Johns Hopkins University, Baltimore, Maryland, USA
3. Department of Molecular Microbiology and Immunology, Johns Hopkins School of Public Health, Baltimore, Maryland, USA
4. Department of Molecular Biology, Massachusetts General Hospital, Boston, Massachusetts, USA
5. Santa Fe Institute, Santa Fe, New Mexico, USA