They evaluated the tetramer 68Ga-DOTA-4P(FAPI)4, 64Cu-DOTA-4P(FAPI)4, and 177Lu-DOTA-4P(FAPI)4 for tumor uptake, biodistribution, intra-tumor retention time, and therapeutic efficacy in HT1080-FAP and U87 models. This evidence concerns the gene FAP and neoplasm.