ERBB2 and cancer: Benefiting from the ingenious molecular design that accurately brings cytotoxic drugs into cancer cells, T-DM1 and trastuzumab deruxtecan (T-DXd) have been gradually expanded indications with excellent efficacy.5, 6, 7 However, the antibody-independent internalization and the premature release of payload in circulation have been reported to cause undesirable toxicities in HER2-targeted ADCs.8