Lack of substantial differences between CF and non-CF SMG transcripts are consistent with the observation that early CF host-defense defects in antimicrobial activity and mucociliary clearance are reproduced simply by preventing Cl− and HCO3− secretion; these interventions that acidify the pH, decrease liquid secretion and increase protein concentration, functions mediated directly by CFTR anion channels (18, 20). Here, CFTR is linked to cystic fibrosis.