CFTR and cystic fibrosis: We confirmed this result in lung of CF mice homozygous for the F508del-CFTR mutation (F508del/F508del) (2.59 ± 0.37 ng/μg of proteins) compared to the WT (+/+) mice (1.91 ± 0.25 ng/μg of proteins) (n = 3, measurements in triplicate) (Figure 1B).