Even though a constant total peptide amount of 20 pmol was injected for all radiopeptides studied, [68Ga]Ga-DOTA-[(N-Me)1Nal8]MGS5 showed a significantly lower uptake in CCK2R-positive tumor xenografts (15.67 ± 2.21% IA/g vs. 23.25 ± 4.70% IA/g for [68Ga]Ga-DOTA-MGS5, p ≤ 0.05). The gene discussed is CCKBR; the disease is neoplasm.