{"type":"root","children":[{"type":"paragraph","children":[{"type":"text","value":"Mucins are high molecular weight glycoproteins synthesized by secretory epithelial cells as membrane-bound or secreted products. Mucins form a physical barrier that protects epithelial cells from stressed-induced damage. Mucins are characterized by tandem repeat regions rich in threonine and/or serine, which are o-glycosylation sites. Mucin 6 (MUC6) is highly expressed in gastric mucosa, duodenal Brunner"},{"type":"text","value":"'"},{"type":"text","value":"s glands, gallbladder, seminal vesicle, pancreatic centroacinar cells and ducts, and periductal glands of the common bile duct; focal expression is seen in basal endometrial and endocervical glands. Abnormal MUC6 expression has been reported from a variety of cancers such as gastric adenocarcinoma, esophageal adenocarcinomas, pancreatic and bile duct adenocarcinoma, and there is growing evidence for a role in tumor development and progression."}]}]}