CCKBR and neoplasm: A high level of radioactivity was found in A431-CCK2R tumor tissue with uptake values of 28.08 ± 6.35% IA/g, resulting in a tumor-to-kidney ratio of 4.41 ± 0.40, a tumor-to-stomach ratio of 11.03 ± 2.05 and tumor-to-blood ratio of 13.38 ± 1.77.