Among the three heterodimers, [111In]In-BQ7812, withPhe and the short PEG linker, demonstrated the best affinity towardPSMA (IC50 = 102 ± 80 nM) and thus was selected forbiodistribution studies,42 where it showedspecific uptake (1 h pi, 16.10 ± 2.96% ID/g) for the PC-3-piptumor (PSMA+/ GRPR+) and high kidney uptake (64.87 ± 27.26% ID/g).42 The same ligand was labeled with 68Ga [68Ga]Ga-BQ7812 in a later study,52 where it showed a similar pharmacokinetic profile (tumor,10.4 ± 1.0% ID/g; kidneys, 45 ± 16% IA/g). This evidence concerns the gene GRPR and neoplasm.