Mucociliary clearance (MCC) is an important part of airway innate defense and is impaired in CF subjects and CF animal models. Five main components contribute to mucociliary clearance: airway submucosal gland secretion; airway surface epithelial secretion; airway surface epithelial fluid absorption; ciliary beat frequency; and airway diameter, controlled via airway smooth muscle tension. Dr. Nam Soo Joo discusses his research on submucosal gland secretion and mucociliary clearance in cystic fibrosis airways. Dr. Joo conducts his research in Dr. Jeff Wine's CF Lab at Stanford, with the support of CFRI.