KRAS and neoplasm: In vivo imaging of mice administered with 5 or 50 nM of anti-Kras nanobeacons or nonsense nanobeacons (50 nM) revealed that only nanobeacons anti-Kras were able to promote efficient and sustained detection of primary gastric tumor (Fig. 2A,B), with an approximately 60% tumor size reduction 5 days after intravenous injection, when compared to nonsense nanobeacon.