CA27-29

**Semantic type:** Amino Acid, Peptide, or Protein|Immunologic Factor

**Definition:** An antigenic epitope that is a 20 amino acid sequence from the extracellular portion of the transmembrane protein mucin-1 (MUC1). Overexpression of MUC1 induces the shedding of its extracellular domain into the bloodstream. Increased MUC1 in the blood may be a marker for breast cancer.

**Synonyms:** - CA 27-29 - CA 27.29 - CA27.29 - Cancer Antigen 27-29 - Cancer Antigen 27.29