To address the issue of lymph node metastasis in breast cancer, Zhu et al. [182] developed a multifunctional nanoprobe (NP-mAb) based on upconversion nanoparticles (NaGdF4:Yb, Tm@NaLuF4), which is modified with PEG and anti-HER2 monoclonal antibody (trastuzumab) for efficient targeting and enrichment of lymph node metastases. The gene discussed is ERBB2; the disease is breast cancer.