ERBB2 and breast carcinoma: Given TNBC molecular heterogeneity, targeting tumour-specific alterations could significantly improve the outcome of the 60–70% of patients with TNBC who do not fully respond to chemotherapy.5 As dysregulated expression of human epidermal receptor (HER) family members is frequent in breast cancer, and given their crucial role in proliferation,9 these receptors have been extensively investigated as targets for anticancer therapy, particularly HER1, HER2 and HER3.