.Attribute Medicine, Posted online: 13 September 2024 doi:10.1038/ s41591-024-03261-7In the non-randomized period 3b/4 DESTINY-Breast12 study, trastuzumab deruxtecan (T-DXd) treatment of patients along with HER2+ enhanced breast cancer cells and also active or secure brain metastases showed constant intracranial task and also systemic effectiveness of T-DXd.