{"type":"root","children":[{"type":"paragraph","children":[{"type":"text","value":"Mucin 1 (MUC1) is a membrane-bound, glycosylated phosphoprotein in the mucin family. The protein is anchored to the apical surface of glandular and ductal epithelial cells and some hematopoietic cells by a transmembrane domain. The degree of glycosylation varies with cell type. Mucins are high molecular-weight glycoproteins which constitute the major component of the mucus layer that protects the gastric epithelium from chemical and mechanical aggressions. The MUC1 protein serves a protective function by binding to pathogens and also functions in a cell-signaling capacity. Overexpression, aberrant intracellular localization, and changes in glycosylation of this protein have been associated with cancer growth, metastasis, and resistance to therapy."}]}]}