Trastuzumab (Herceptin), an FDA-approved humanized monoclonal antibody (mAb) targeting the extracellular domain IV of HER2, inhibits cancer cell proliferation by mediating antibody-dependent cellular cytotoxicity (ADCC), preventing HER2 cleavage into a constitutively active form, and triggering HER2 internalization and degradation [10]. Here, ERBB2 is linked to cancer.