About the Authors
Department of Human Genetics, University of Chicago, Chicago, Illinois, United States of America
The authors have declared that no competing interests exist.
Conceived and designed the experiments: C Sun, R Kittler, A Di Rienzo. Performed the experiments: C Sun, C Southard. Analyzed the data: C Sun, DB Witonsky, R Kittler, A Di Rienzo. Wrote the paper: C Sun, R Kittler, A Di Rienzo.