About the Authors
Department of Pediatrics, University of Iowa College of Medicine, Iowa City, Iowa, United States of America
Howard Hughes Medical Institute, Chevy Chase, Maryland, United States of America
Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, California, United States of America
The authors have declared that no competing interests exist.
Conceived and designed the experiments: SS MVN VCS. Performed the experiments: SS QZ KB DKB CCS. Analyzed the data: SS MVN VCS. Wrote the paper: SS VCS.