ERBB2 and neoplasm: We performed 2 experiments with our BsAb in immunocompetent hmHER2Tg mice with D5-HER2 tumors: one in which we started treatment on day 1 after tumor cell inoculation (Figure 6) and the other in which we started treatment on day 3 after tumor cell inoculation, when tumors were well established (Figure 7).