MUC5AC and cystic fibrosis: To test the potential relationship in HBECCs between mucin stores and baseline secretion we compared the output of mucins from cultures grown under control conditions with those in which inflammatory mucous hyperplasia/hypertrophy was induced by a supernatant of mucopurulent material (SMM; [41–43]), collected and prepared from lungs removed from patients with Cystic Fibrosis during organ transplant surgeries.