The pulmonary ionocytes express Forkhead box I1 (FoxI1), multiple subunits of the V-ATPase (Atp6v1c2 and Atp6v0d2), Cochlin, ASCL3, and the cystic fibrosis (CF) transmembrane conductance regulator (CFTR). Here, FOXI1 is linked to cystic fibrosis.