The Calu-3 cell line is a well characterized model of the airway epithelial barrier and has been frequently used to study the uptake and transepithelial transport of drugs. To resemble a chronic inflammatory state, as observed in many pulmonary diseases, such as Asthma and COPD, the cells are treated with LPS. The efficacy of anti-inflammatory drugs is then measured by means of functionality, i.e. reduction of proinflammatory cytokine secretion. Further endpoints addressing toxicity or specific cellular effects (e.g. mucus production) can be included in the model.