There were errors in the Funding section. The correct funding information is as follows: This work was supported by grants from CIBER de Enfermedades Respiratorias, Instituto de Salud Carlos III, Spain (CB06/06/1088); Instituto de Salud Carlos III, Spain (PI 10/0393, PI 11/00840); Regional European Social Funds (FEDER). EPR holds a “Sara Borrel” contract from Instituto de Salud Carlos III, Spain. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
Footnotes
Competing Interests: No competing interests declared.