Neratinib is an irreversible pan‐HER tyrosine kinase inhibitor (TKI) approved in 2017 by the US Food & Drug Administration as monotherapy for the extended adjuvant treatment of patients with HER2‐positive early‐stage breast cancer (EBC) following adjuvant trastuzumab‐based therapy and in combination with capecitabine for patients with HER2‐positive metastatic breast cancer (MBC) (Food & Drug Administration, 2022). The gene discussed is ERBB2; the disease is breast cancer.