The fraction of exhaled nitric oxide (FENO) is a biomarker for type 2 asthma, reflecting the degree of local pulmonary inflammation linked to immune pathways, including interleukin (IL)-13 [1]. In clinical practice, FENO is a reliable marker for inhaled corticosteroid (ICS) responsiveness [2] and the efficacy of biological therapies, such as those targeting IL-4/IL-13 pathways [3, 4], as well as the detection of steroid nonadherence or resistance in severe asthma [2]. The prospective Severe Asthma Registry of the German Asthma Net (GAN) enrols patients with severe asthma for in-depth assessment of phenotypes, underlying mechanisms and therapeutic strategies; GAN has been approved by respective ethics committees, with all included patients having signed informed consent [5]. Prior studies of FENO either included patients with asthma of any severity [6] or did not involve a comprehensive analysis in a large cohort [7]. We therefore used cross-sectional data from GAN to determine the correlation of FENO with epidemiological, laboratory, clinical, lung function, or quality of life parameters and the need for oral corticosteroid (OCS) maintenance therapy in a carefully selected severe asthma cohort to better characterise the severe asthma subtype with high FENO values. In a severe asthma cohort of 1007 patients, high FENO was associated with chronic rhinosinusitis/polyps, later asthma onset, poor lung function and asthma control, low quality of life, frequent exacerbations and the need for maintenance OCS. #GANregistry https://bit.ly/3sNrtIQ