{"type":"root","children":[{"type":"paragraph","children":[{"type":"text","value":"Mucin 5AC (MUC5AC) is a large, highly glycosylated protein in the mucin protein family. It is found in bronchial epithelium, bronchial submucosal glands, nasal mucosa, gastric epithelium, endocervix epithelium, and submucosal glands. It is highly oligomerized, which makes it an ideal gel-forming molecule. The expression of MUC5AC in airway epithelial cells is regulated by various neurohumoral factors and inflammatory mediators. Overexpression of MUC5AC can be observed in various cancers and contributes to tumor development, progression, and metastasis."}]}]}