ERBB2 and neoplasm: The targeting specificity of 99mTc-ADAPT6-ABD-mcDM1 was confirmed in two ways, by saturation of binding sites on HER2 using trastuzumab, which appreciably lowered tumor uptake, and by comparison with the tumor uptake of the non-targeted control, 99mTc-ADAPTNeg-ABD-mcDM1 (Figure 7), which was appreciably lower than the uptake of 99mTc-ADAPT6-ABD-mcDM1.