About the Authors
Department of Genetics, Dartmouth Medical School, Hanover, New Hampshire, United States of America
The Microsoft Research–University of Trento Centre for Computational and Systems Biology, Povo (Trento), Italy
The authors have declared that no competing interests exist.
Conceived and designed the experiments: CIH ACN. Performed the experiments: CIH JZ. Analyzed the data: CIH JZ ACN. Wrote the paper: CIH ACN.