CRP and cystic fibrosis: We measured CRP because it is used broadly as a clinical marker of systemic inflammation, and has also been evaluated in a number of studies as a biomarker to detect onset of CF pulmonary exacerbation, efficacy of treatment of CF exacerbations, or severity of CF lung disease (with one parameter for disease severity being whether or not subjects have chronic P. aeruginosa infection) (Sharma et al., 2017; Loh et al., 2018; Sagel et al., 2019).