ERBB2 and breast cancer: Although previous studies have demonstrated the beneficial effects of afucosylation or S239D/I332E individually in trastuzumab (30, 35), our study is the first to combine glycoengineering and direct point mutation strategies into the same antibody structure to generate WT and Fc-engineered antibodies targeting two breast cancer–associated antigens, HER2 and the emerging TNBC target FRα (5).