In previous studies, the combination of trastuzumab with pertuzumab was a more effective therapy than mono-therapies in the clinic.40, 41, 42 Moreover, a triparatopic tribody, consisting of three non-overlapping ErbB2 binders, was efficient in downregulating ErbB2 and inhibiting tumor cell growth on Her2-positive tumor cells, including trastuzumab-resistant cell lines.29 The gene discussed is ERBB2; the disease is neoplasm.