Anti-Herstatin antibodies are protein reagents that detect specific antigens. The Herstatin antigen is another term for the human protein erb-b2 receptor tyrosine kinase 2, encoded by the ERBB2 gene. The protein is known to function in receptor-mediated signaling pathways and cardiac tissue development, among other biological roles. Canonically, it has an amino acid length of 1255 residues and a mass of 137.9 kilodaltons. Its subcellular localization is in the cell membrane and it is reported to be expressed in a variety of tumor tissues including primary breast tumors and tumors from small bowel, esophagus, kidney and mouth. The Herstatin protein is a member of the Tyr protein kinase protein family. Other alias names for Herstatin include CD340, HER-2, and HER-2/neu. Some Herstatin antibodies may have been used in research and have associated citations. Western Blot is a widely used application for these antibodies. ELISA and Immunohistochemistry are also common applications.