HER2, or human epidermal growth factor receptor 2, is a protein on the exterior of many cells and may be overexpressed on some cancer cells, specifically, in breast and gastric cancer. In some cancers, the gene that codes for the HER2 receptor may be amplified and lead to overexpression of the receptor on the cell surface.

Anti-HER2 drugs are valuable in the treatment of HER2-positive.

Determining the HER2 status in cancers helps guide treatment for patients. This is typically included in a patient’s pathology report, and identifies which patients may be benefitted with anti-HER2 therapy drugs.

  • Immunohistochemistry (IHC) tests detect HER2 receptors on the surface of cancer cells.

Fluorescence in situ hybridization (FISH) detects if the HER2 gene in cells is amplified.