Lapatinib, neratinib, and pyrotinib are small HER2 tyrosine-kinase inhibitors that can bind to the ATP site of the receptor intracellular domain, block HER2 dimerization, interfere with signal transduction related to tumor cell proliferation and growth, and display excellent efficacy for HER2+ BC [38]. The gene discussed is ERBB2; the disease is neoplasm.