The bombesin antagonist conjugated to the sarcophagine (3,6,10,13,16,19-hexaazabicyclo[6.6.6]icosane = Sar) derivative 5-(8-methyl-3,6,10,13,16,19-hexaaza-bicyclo[6.6.6]icosan-1-ylamino)-5-oxopentanoic acid (MeCOSar) via PEG4 (SAR-BBN) has been previously evaluated after radiolabeling with 64Cu and demonstrated good in vitro binding and high PC-3 tumor uptake in mice [14] (Figure 1). The gene discussed is GRP; the disease is neoplasm.