On January 17, 2025, the FDA approved the use of Dato-DXd for adult patients with unresectable or metastatic, HR-positive, HER2-negative (IHC 0, IHC 1+, or IHC 2+/ISH−) breast cancer who have received prior endocrine-based therapy and chemotherapy for unresectable or metastatic disease based on the efficacy and safety results obtained from the TROPION-Breast01 (NCT05104866) trial (34). The gene discussed is ERBB2; the disease is breast carcinoma.