Liu C, et al. - The clinical application of exhaled nasal nitric oxide (nNO) were comprehensively investigated, in distinguishing between chronic rhinosinusitis (CRS) with nasal polyps (CRSwNP) and CRS without nasal polyps (CRSsNP) in consideration of the atopic status of patients. The findings illustrated that exhaled nNO levels could assist in distinguishing between patients with CRSwNP and patients with CRSsNP. Nonetheless, the atopic status of the patient exerted an impact on the use of nNO as a diagnostic or monitoring biomarker in CRS.