Three types of MPs expressing epithelial-specific markers, EpCAM(+)MPs, E-cadherin(+)MPs, and Integrin β6 (ITGB6)(+)MPs, were measured in NLFs to compare status of epithelial injury and repair among controls, CRSsNP, CRSwNP, and aspirin-exacerbated respiratory disease (AERD), a severe form of CRSwNP with history of aspirin hypersensitivity, difficult to control comorbid asthma, and frequently recurrent polyposis after surgery [37]. This evidence concerns the gene ITGB6 and chronic rhinosinusitis without nasal polyps.