Intravenous administration of an 18-fold molar excess of non-radiolabelled trastuzumab 24 h prior to administration of 111In-(HE)3-G3 did not alter HER2-positive tumour uptake at 4 h compared with that in control mice receiving only 111In-(HE)3-G3 (7.2 ± 1.3 vs. 7.1 ± 1.9 % ID/g, respectively; Fig. 6c). This evidence concerns the gene ERBB2 and neoplasm.