CCKBR and neoplasm: DOTA-MGS5 radiolabeled with different radiometals was efficiently stabilized against enzymatic degradation in vivo and showed a highly increased tumor uptake (>20% IA/g) combined with improved tumor-to-kidney ratio (4-6) in nude BALB/c mice xenografted with A431 cells transfected with human CCK2R (A431-CCK2R) [14].