CFTR and cystic fibrosis: While non-CF epithelia absorbed after 24 and 48 h 1.67 ± 0.15 μl/h/cm2 (n = 5) and 1.06 ± 0.06 μl/h/cm2 (n = 7), respectively, in F508del-CFTR epithelia net absorpion rate was 2.25 ± 0.19 μl/h/cm2 (n = 5) and 1.58 ± 0.07 μl/h/cm2 (n = 7) (Figure 5).