In contrast, for the 28 individuals in the “CF suspicion” group who showed lumen-negative responses, i.e., normal CFTR function (Isc-CCH(IBMX/Fsk) = −153.38±15.33 μA/cm2 vs Isc-CCH(IBMX/Fsk) = −162.07±19.64 μA/cm2 in the non-CF control group) we could only detect one CF-causing mutation (F508del) in one individual (being thus a CF-carrier) and 2 other mutations in two individuals who were thus compound heterozygous: W1282X/4428insGA and F508del/D1152H, respectively (Table S1). Here, CFTR is linked to cystic fibrosis.