ERBB2 and breast carcinoma: The clinical efficacy of neratinib in metastatic HER2 mutant solid tumors, including breast cancer, was recently described in a landmark “basket” trial.31 In the study by Hyman et al., an objective response rate of 32% (95% CI: 15–54%) was noted in patients with HER2-mutant breast cancer (N = 25), with responsive tumors having mutations in extracellular domains as well as the tyrosine kinase domain.