The binding affinities of Ga-TacsBOMB2, Ga-TacsBOMB3, Ga-TacsBOMB4, Ga-TacsBOMB5, Ga-TacsBOMB6, and Ga-RM2 were measured by a cell-based binding assay using GRPR-expressing PC-3 prostate cancer cells. Here, GRPR is linked to Familial prostate cancer.