FeNO testing in severe asthma: A clinical argument or an access constraint?

Funding Information: In the preparation of this article, the authors received collaboration from the medical writer Duarte Oliveira (W4Research) financially supported by Sanofi. Sanofi had no role in the preparation of the manuscript or in the decision to submit the manuscript for publication. All authors declare collaborating and receiving fees from Sanofi and other pharmaceutical companies either through participation in advisory boards or consultancy, congress symposia, conducting clinical trials, investigator-initiated trials or grants. Copyright: Copyright 2021 Elsevier B.V., All rights reserved.