About the Authors

Jill M. Ferdinands

To whom correspondence should be addressed. E-mail: zdn5@cdc.gov

Affiliation Air Pollution and Respiratory Health Branch, Division of Environmental Hazards and Health Effects, National Center for Environmental Health, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America

David M. Mannino

Affiliation Division of Pulmonary, Critical Care, and Sleep Medicine, University of Kentucky College of Medicine, Lexington, Kentucky, United States of America

Marta L. Gwinn

Affiliation National Office of Public Health Genomics, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America

Molly S. Bray

Affiliation Department of Pediatrics, Baylor College of Medicine, Houston, Texas, United States of America

Competing Interests

DM serves on advisory boards for Boehringer Ingelheim, GSK, and Ortho Biotech, is on the speakers' bureau for Boehringer Ingelheim, Pfizer, and Dey, and has received research grants from GSK and Pfizer. JF, MB, and MG declare that they have no competing interests.

Author Contributions

Conceived and designed the experiments: MG JF DM MB. Performed the experiments: JF DM. Analyzed the data: MG JF DM MB. Contributed reagents/materials/analysis tools: MB. Wrote the paper: JF DM. Other: Conceived of the study, participated in its design and coordination, and helped to draft the manuscript: MG. Participated in study design, conducted the molecular genotyping, and reviewed the manuscript: MB.