Consistent with previous results24,37,38, in ileal tissues from both WT mice and non-CF human controls, I-FABP labelling was observed in the cytoplasm and SGLT1 labelling on the brush border membrane of absorptive enterocytes along the entire length of crypt-villus axes (Figs. 8A and C). Here, SLC5A1 is linked to cystic fibrosis.