Neratinib, an oral, small-molecule TKI of HER family members, was approved for extended adjuvant treatment in early-stage HER2-overexpressing/amplified breast cancer after completion of adjuvant trastuzumab-based therapy.9 In an earlier phase II study, neratinib as monotherapy in HER2-positive MBC demonstrated an overall response rate of 24% in trastuzumab-refractory patients and 56% in trastuzumab-naïve patients.10 This evidence concerns the gene ERBB2 and breast carcinoma.