The results from the DESTINY-Breast06 (DB-06) study further confirm that T-DXd significantly improves PFS in patients with HR+, HER2-low/ultralow advanced BC who have been previously treated with endocrine therapy.33 Similar therapeutic efficacy has been noted in patients with HER2-low-expression metastatic BC treated with other ADCs such as SYD985 and SG.34-36 Therefore, ADC therapy stands as a promising significant therapeutic modality for advanced HER2-low-expression BC. Here, ERBB2 is linked to breast cancer.