ERBB2 and neoplasm: The results demonstrated that at one hour following intravenous injection, 2Rs15d-99mTc had a high concurrent tumor-to-muscle (49.6 ± 11.8 at 1 h p.i.)and tumor-to-blood (16.4 ± 3.6 at 1 h p.i.)ratio, low accumulation in nontarget organs other than the kidneys, strong tumor uptake in HER2 positive tumor models, and rapid blood clearance [71].