Used in targeted cancer therapy, particularly for HER2-positive breast and gastric cancers. Binds specifically to the HER2 receptor, inhibiting cell proliferation and promoting immune-mediated destruction of cancer cells. Employed in diagnostic applications to detect HER2 overexpression in tumor tissues. Serves as a reference standard in the development of biosimilars and therapeutic antibodies. Supports research in oncology for understanding HER2 signaling pathways and treatment resistance mechanisms.