1. Broad Institute of Massachusetts Institute of Technology (MIT) and Harvard, Cambridge, MA 02142, USA.
2. McGovern Institute for Brain Research, MIT, Cambridge, MA 02139, USA.
3. Department of Brain and Cognitive Science, MIT, Cambridge, MA 02139, USA.
4. Department of Biological Engineering, MIT, Cambridge, MA 02139, USA.
5. Department of Biology, MIT, Cambridge, MA 02139, USA.
6. Department of Systems Biology, Harvard Medical School, Boston, MA 02115, USA.
7. Harvard-MIT Division of Health Sciences and Technology, MIT, Cambridge, MA 02139, USA.