On the diagnostic front, through the conjugation of specific targeting moieties (such as antibodies or ligands targeting HER2, estrogen receptor (ER), protein ligand-1 (PD-L1), etc.), nanoprobes can achieve highly sensitive recognition of breast cancer-associated molecular biomarkers, providing powerful tools for early disease detection, intraoperative navigation, and dynamic therapeutic monitoring [9,10]. The gene discussed is ESR1; the disease is breast cancer.