Nevertheless, as particularly [99mTc]Tc-N4-asp-[Bta8]MJ9 revealed a favorable biodistribution profile and [99mTc]Tc-MIP-1404 demonstrated high uptake in liver and duodenum in prostate cancer patients, there might be a potential for the GRPR ligand that exhibited improved tumor-to-abdomen contrast preclinically. This evidence concerns the gene GRPR and prostate cancer.