ERBB2 and breast cancer: Lapatinib (GW572016, Tyverb, GlaxoSmithKline), a dual HER1–HER2 reversible inhibitor, was the first TKI approved for metastatic HER2 BC and is still the only one recommended in combination with endocrine therapy (letrozole) and/or chemotherapy (capecitabine) for hormone receptor-positive (HR+)/HER2+ advanced or metastatic tumors [60].