For our proof of principle study, we chose a homodimeric PESIN (PEG3‐BBN7‐14) backbone to address the gastrin‐releasing peptide receptor (GRPR) which is overexpressed on different cancers.[9b, 18d, 19] Although the endogenous ligand for the GRPR, the 27‐amino acid receptor ligand bombesin (BBN), exhibits a high affinity towards its target, it is also known to suffer from a low in vivo stability. The gene discussed is GRPR; the disease is cancer.