CFTR and cystic fibrosis: We assessed cholinergic and cAMP-CFTR-mediated Cl- secretion in 150 freshly excised rectal biopsies from 40 individuals, including patients with confirmed CF clinical diagnosis (n = 17), individuals with clinical CF suspicion (n = 16) and non-CF controls (n = 7) not in accordance with the original Rotterdam protocol but with the SOP ICM_EU001, V.2.7.