Results from studies such as DESTINY‐Breast03 [1] and DESTINY‐Breast04 [2] demonstrate that T‐DXd not only significantly improves survival in patients with HER2‐positive advanced breast cancer but also provides clinical benefit to patients with HER2‐low advanced breast cancer from HER2‐targeted therapy [3, 4, 5]. The gene discussed is ERBB2; the disease is breast carcinoma.