Precisely distinguishing between HER2‐zero, HER2‐low, and HER2‐positive is crucial for identifying potential beneficiaries of ADCs therapies.[3, 4] Recent clinical trials have demonstrated that patients with HER2‐low breast cancer significantly benefit from novel HER2‐targeted ADCs.[3, 5] Unlike HER2‐positive patients who traditionally respond to HER2‐targeted therapies, HER2‐low patients were previously classified as HER2‐negative and lacked effective targeted treatment options. The gene discussed is ERBB2; the disease is breast cancer.