GRPR and posterior cortical atrophy: As previously mentioned, RGD-BBN-based heterodimers which can dual-target integrin αvβ3 and GRPR have shown great potential in solid tumor molecular imaging, especially for breast cancer and PCa models, by combining tumor vascular targeting specificity of RGD peptides (binding to integrin αvβ3) with the tumor-cell receptor targeting affinity of BBN analogs (binding to GRPR).