About the Authors

Windy A. Boyd

Affiliation Laboratory of Molecular Toxicology, National Toxicology Program, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina, United States of America

Sandra J. McBride

Affiliation Nicholas School of the Environment and Earth Sciences, Duke University, Durham, North Carolina, United States of America

Jonathan H. Freedman

To whom correspondence should be addressed. E-mail: freedma1@niehs.nih.gov

Affiliations Laboratory of Molecular Toxicology, National Toxicology Program, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina, United States of America, Nicholas School of the Environment and Earth Sciences, Duke University, Durham, North Carolina, United States of America

Competing Interests

The authors have declared that no competing interests exist.

Author Contributions

Conceived and designed the experiments: WB JF. Performed the experiments: WB. Analyzed the data: SM. Contributed reagents/materials/analysis tools: JF. Wrote the paper: WB SM.