Used in research and development for targeted cancer therapies, particularly in breast and gastric cancers overexpressing HER2. Enables detection and purification of HER2 proteins in immunoassays and affinity chromatography. Supports the development of monoclonal antibodies and biosimilars by providing a stable, soluble form of the HER2 extracellular domain. Facilitates binding studies and high-throughput screening of therapeutic candidates targeting the HER2 pathway.