[111In]In-DOTA-trastuzumabIgG and F(ab')2 exhibited high tumor uptake of 10.6± 0.6% ID/g and 8.6 ±1.5% ID/g, respectively at 2 d p.i. in mice with s.c. HER2-positive164/8-1B/H2N.luc+ human BC xenografts (Figure 3). The gene discussed is ERBB2; the disease is breast cancer.