In breast cancer, Ferreira and coworkers developed a novel dual-receptor heterodimeric peptide probe, 99mTc-HYNIC-cRGDfk-NPY, composed by a RGD sequence, which targets tumor angiogenesis by recognizing integrin αVβ3, and a neuropeptide Y (NPY) receptor, which is overexpressed in 90% of human breast tumors. This evidence concerns the gene NPY and breast neoplasm.