ATP12A and cystic fibrosis: It has been previously published that airway epithelial cells do not express the gastric H+ pump and this was confirmed in our cells in which we found an average Ct value of 37.50 ± 1.53 in CF hAECs and 40 in non-CF hAECs (compared to averaged values of 21.61 ± 0.21 in CF cells and 22.03 ± 0.66 in non-CF cells for ATP12A, Supplementary Figure 4).