Overall, HER2DX is the first combined prognostic score based on clinicopathological and genomic variables in early-stage HER2+ breast cancer, which identifies a substantial proportion of patients who might not need additional therapies, such as pertuzumab, neratinib, or T-DM1 because of their favorable survival outcomes with chemotherapy and trastuzumab. Here, ERBB2 is linked to breast carcinoma.