All 99mTc-labeled MJ9 derivatives revealed similarly low activity levels in all organs (<4.5 percent injected dose per gram; %ID/g), except for the GRPR-positive pancreas (4.7–39.0 %ID/g) and the PC-3 tumor (9.3–14.6 %ID/g) at 1 h p.i., which indicates a rapid clearance from off-target tissues. This evidence concerns the gene GRPR and neoplasm.