CFTR and asthma: The findings of this study of patients with asthma and airway mucus hypersecretion suggest the following: (1) a significantly high percentage of patients express the NM_000492.3(CFTR):c.1680-870T>A polymorphism in the CFTR gene, and (2) these patients tend to be older, have greater asthma severity and poorer clinical control and have a non-allergic inflammatory phenotype.