Therapeutic regimens approved for HER2+ BC include anti-HER2 monoclonal antibodies (mAbs) (such as trastuzumab, pertuzumab and margetuximab), or tyrosine kinase inhibitors (TKIs) (such as lapatinib, neratinib and tucatinib), generally combined with chemotherapy, and antibody drug conjugates (ADCs) such as trastuzumab emtansine (T-DM1) and trastuzumab deruxtecan (T-DXd) [47]. The gene discussed is ERBB2; the disease is breast cancer.