Bicarbonate is a fundamental ion in cellular pH regulation and crosses the membrane via various bicarbonate transporters, such as the chloride/bicarbonate exchangers (CBE; SLC26A family and anion exchanger (AE) family), sodium/bicarbonate cotransporter (NBC), sodium-dependent chloride–bicarbonate exchanger (NDCBE), and the cystic fibrosis (CF) transmembrane conductance regulator (CFTR) channel [1,2,3,4,5]. This evidence concerns the gene SLC4A4 and cystic fibrosis.