Used in targeted cancer therapy, particularly for HER2-positive breast and gastric cancers. Binds specifically to the HER2 receptor on cancer cells, enabling precise delivery of cytotoxic agents when conjugated with drugs, as seen in antibody-drug conjugates like disitamab vedotin. Triggers immune-mediated cell destruction through mechanisms such as antibody-dependent cellular cytotoxicity (ADCC). Also employed in diagnostic applications to detect HER2 overexpression in tumor tissues, guiding treatment decisions. Its high specificity minimizes damage to healthy cells, improving therapeutic efficacy and reducing side effects.