invasion, and cell detachment. Bile acids have been found to stimulate carcinogenesis in pancreatic ductal adenocarcinoma cells through increased expression of MUC4. Esophageal MUC4 expression in esophageal cancer often leads to increased tumor proliferation and migration. Like with prostate cancer, increased expression of MUC4 suggests greater development of esophageal cancer. Bile acids present in gastroesophageal reflux disease are thought to contribute to this over-expression of MUC4. By inhibiting MUC-4, scientists have been able to reduce cancer cell proliferation, migration, and tumor size as well as reduce protein S100A4 expression, presenting MUC-4 as a good therapeutic target for the treatment of esophageal cancer. Breast Unlike pancreatic and esophageal cancers, MUC4 expression is suppressed in the primary tumor when compared to normal cells. It, however, is found to be overexpressed in lymph node metastases. The initial reduction in MUC-4 appears to promote the transition to the primary tumor, but its subsequent increase in expression facilitate metastasis and ultimately increased malignancy Other MUC4 is found to be overexpressed in papillary thyroid carcinoma, and could serve as a potential marker of malignancy and prognosis. MUC-4 is also found to be a very sensitive and specific marker in low-grade fibromyxoid sarcoma. Role in other diseases MUC-4 is also relevant to several other disease conditions. Polymorphisms in the MUC4 gene have been found to play a role in the progression of endometriosis and related infertility, as well as dysplastic cervical disorders. MUC-4 also has important roles in inflammatory bowel disease such as Crohn's disease and is found to be overexpressed in ulcerative colitis. References 04