ERBB2 and breast cancer: The emergence of new anti-HER2 targeted therapies, such as pertuzumab3, margetuximab4, lapatinib5, pyrotinib6, neratinib7, tucatinib8, trastuzumab emtansine (T-DM1)9, trastuzumab deruxtecan (T-DXd)10,11, and trastuzumab duocarmycin12, has resulted in great progress in the treatment of HER2+breast cancer.