The conductance (G) values obtained in non-CF epithelia (14,732 ± 1267 μS/cm2, n = 10) were significantly higher than those obtained in CF epithelia (5727 ± 1299 μS/cm2, n = 10), consistently with the virtually null expression of CFTR in the apical membrane of mutant cells (Figure 1a). Here, CFTR is linked to cystic fibrosis.