Asthma is an inflammatory disorder of the airways, which causes attacks of wheezing, shortness of breath, chest tightness, and coughing in patients. Degrees of severity are unique to individual patients as are responses to drug treatments. Adhesion of eosinophils to bronchial epithelial cells, and the interaction of airway smooth muscle and sub-epithelial fibroblasts play a critical role in asthma pathology. During an asthma attack bronchiole smooth muscle tissue can constrict and decrease the flow of air in the airways. The amount of air flow can further be decreased by inflammation or excess mucus secretion.Cryopreserved Diseased Bronchial Epithelial cells test negative for mycoplasma, bacteria, yeast, and fungi. HIV-1, hepatitis B and hepatitis C are not detected for all donors and/or cell lots. A Certificate of Analysis is provided for each cell lot purchased. Our catalog number 00194911S are suitable for air-liquid interface studies and are guaranteed to promote full differentiation of the airway epithelium expressed by the formation of a polarized epithelium with good barrier function (transepithelial resistance), secretory phenotype (mucin secretion) and ciliogenesis. Differentiation usually will occur by day 22 in culture.