About the Authors

XueLiang Guo

Affiliation Cystic Fibrosis/Pulmonary Research and Treatment Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America

Rhonda G. Pace

Affiliation Cystic Fibrosis/Pulmonary Research and Treatment Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America

Jaclyn R. Stonebraker

Affiliation Cystic Fibrosis/Pulmonary Research and Treatment Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America

Clayton W. Commander

Affiliation Cystic Fibrosis/Pulmonary Research and Treatment Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America

Anthony T. Dang

Affiliation Cystic Fibrosis/Pulmonary Research and Treatment Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America

Mitchell L. Drumm

Affiliation Departments of Pediatrics and Genetics, Case Western Reserve University, Cleveland, Ohio, United States of America

Ann Harris

Affiliation Human Molecular Genetics Program, Children's Memorial Research Center, Northwestern University Feinberg School of Medicine, Chicago, Illinois, United States of America

Fei Zou

Affiliation Department of Biostatistics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America

Dallas M. Swallow

Affiliation Research Department of Genetics, Evolution and Environment, University College London, London, United Kingdom

Fred A. Wright

Affiliation Department of Biostatistics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America

Wanda K. O'Neal

Contributed equally to this work with: Wanda K. O'Neal, Michael R. Knowles

Affiliation Cystic Fibrosis/Pulmonary Research and Treatment Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America

Michael R. Knowles

Contributed equally to this work with: Wanda K. O'Neal, Michael R. Knowles

knowles@med.unc.edu

Affiliations Cystic Fibrosis/Pulmonary Research and Treatment Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America, Gene Modifier Study Group, Chapel Hill, North Carolina, United States of America

Competing Interests

The authors have declared that no competing interests exist.

Author Contributions

Conceived and designed the experiments: XLG RGP JRS AH DMS WKO MRK. Performed the experiments: XLG RGP JRS WKO MRK. Analyzed the data: XLG RGP JRS CWC ATD FZ DMS FAW WKO MRK. Contributed reagents/materials/analysis tools: XLG RGP JRS CWC ATD MLD AH FZ DMS FAW WKO MRK. Wrote the paper: XLG RGP JRS CWC FZ DMS FAW WKO MRK.