CFTR and cystic fibrosis: It is well-documented that compromised functions of CFTR and the CFTR-modulated HCO3– secretion in CF result in an abnormal environment of higher salt (∼100 ± 5 mM) (Zabner et al., 1998) and lower pH (∼6.7 ± 0.3) (Chen et al., 2010; Pezzulo et al., 2012; Shah et al., 2016) in the CF ASL than those of normal subjects.