The overexpression of neuropeptide Y receptors in BC cells allows the use of designed compounds for breast tumor imaging (e.g., heterobivalent dual-target peptide for neuropeptide Y and integrin αvβ3 receptors; 18F-labeled triazolyl-linked argininamides, neuropeptide Y analogs labeled with a positron emitter 68Ga; 99mTc-labeled neuropeptide Y short analog) [201,202,203,204,205] and BC treatment (Y1 L-KGRR-FF-IR: an enzyme-responsive precursor based on the neuropeptide Y receptor 1 ligand; chlorin e6 delivery system; neuropeptide Y-decorated gold nanoclusters) [206,207,208,209]. This evidence concerns the gene NPY and breast cancer.