Mucin Peptide MUC-1

**Semantic type:** Carbohydrate|Immunologic Factor

**Definition:** Mucin is expressed by most glandular epithelia. Tandem repeats characterize the core mucin protein, apomucin; variation of the protein derives from variation in the number of expressed repeats. Native forms of mucin are distinct in size and degree of glycosylation; factors other than the primary structure of apomucin may contribute to these characteristics. Many complex O-linked oligosaccharides are presumably added by glycosyltransferases. Expression is increased in the lactating breast and in breast, ovary, lung, and prostate malignancies. It is a serum marker for breast cancer.

**Synonyms:** - CA-15-3 - CA15-3 - CA15-3 Antigen - Cancer Antigen 15-3 - Carbohydrate Antigen 15-3 - Episialin - Muc1 Mucin - Polymorphic Epithelial Mucin