CFTR and cystic fibrosis: Of note, cigarette smoking exposure has been associated with worse clinical prognosis in CF—decreased growth and weight (Rubin, 1990; Kovesi et al., 1993; Kopp et al., 2015), smaller lung function (Kovesi et al., 1993; Smyth et al., 1994; Collaco et al., 2008), increased colonization by MRSA (Kopp et al., 2015), longer periods of intravenous antibiotic treatment (Gilljam et al., 1990), airway surface dehydration (Clunes et al., 2012) and CFTR dysfunction (Cantin et al., 2006b; Raju et al., 2013; Marklew et al., 2019; Rasmussen et al., 2020).