About the Authors
Department of Statistics, University of Chicago, Chicago, Illinois, United States of America
Department of Mathematics, University of California, Berkeley, California, United States of America
Division of Infectious Diseases, Stanford University Medical Center, Stanford, California, United States of America
Genome Technology Center, Stanford University, Palo Alto, California, United States of America
Department of Biosystems Science and Engineering, ETH Zurich, Basel, Switzerland
The authors have declared that no competing interests exist.
Performed the experiments: YM SR CW BG MR RS. Analyzed the data: NE LP NB. Wrote the paper: NE LP NB.