Thus, this agent showed a high potential for dual GRPR- and PSMA-specific targeting, even though the evaluation in only mono-target-expressing PC3 and LNCaP cells is not ideal for the evaluation of the heterobivalent agents in in vitro and in vivo studies as no synergistic effects of heterodimerization on tumor uptakes caused by concomitant binding can be detected. The gene discussed is GRPR; the disease is neoplasm.