111In[In]-BnDTPA-trastuzumab-NLS injection prepared from the kits exhibited high affinity and specific binding to HER2 on SK-BR-3 human BC cells in a direct (saturation) binding assay (Ka = 4.6–6.2 × 108 L/mole; Bmax = 0.9 × 106 binding sites/cell; Table 1 and Fig. 4). The gene discussed is ERBB2; the disease is breast cancer.