References: 1. Data on file. Circassia Ltd March 2018. 2. Alving K, Malinovschi A. Basic aspects of exhaled nitric oxide. Eur Respir Mon. 2010;49:1-31. 3. Peirsman EJ, Carvelli TJ, Hage PY, et al. Exhaled nitric oxide in childhood allergic asthma management: a randomized controlled trial. Pediatr Pulmonol. 2014;49(7):624-631. 4. Dweik RA, Boggs PB, Erzurum SC, et al; on behalf of the American Thoracic Society Committee on Interpretation of Exhaled Nitric Oxide Levels (FENO) for Clinical Applications. An official ATS clinical practice guideline: interpretation of exhaled nitric oxide levels (FENO) for clinical applications. Am J Respir Crit Care Med. 2011;184(5):602-615. 5. Maniscalco M et al. Fractional exhaled nitric oxide-measuring devices: technology update. Medical Devices Evidence and Research. June 2017.