Starting from the notion that CFTR disruption in pigs, but not in mice, produces a lung disease resembling that of humans with CF [15,17,18,19,20,21], by means of in vitro and in vivo studies, Shah and colleagues associated the divergent respiratory phenotypes observed in the three species (humans, pigs and mice) with the differential expression of ATP12A, which was found to be present at the apical membrane of human and pig airway epithelial cells but not in those of mouse airways [15]. This evidence concerns the gene CFTR and cystic fibrosis.