In vivo studies conducted in male nude BALB/c mice bearing subcutaneous PC-3 tumors showed tumor accumulation values of 2.15 ± 0.55% ID/g at 1 h p.i. Tumor uptake was effectively reduced by co-administration of macroscopic amounts of [NOTA-8-Aoc-BBN(7-14)NH2], confirming receptor-mediated uptake of the radioligand for the GRPR [71]. The gene discussed is GRPR; the disease is neoplasm.