ERBB2 and breast cancer: A second generation TKI, neratinib, which irreversibly binds to the kinase domain of HER1, HER2, and HER4 (Wissner and Mansour, 2008), has been approved for use in early-stage HER2+ BC patients who have already undergone a one-year course of trastuzumab treatment (Singh et al., 2018).