One interesting finding from our studies was that the tumor-to-background ratios increased significantly over time up to 24 h after injection (pi) [7, 13] due to the high uptake and long retention in tumors in combination with the fast clearance from blood and GRPR-expressing organs, underscoring the importance of radionuclide half-life in high sensitivity molecular imaging. The gene discussed is GRPR; the disease is neoplasm.