Lapatinib (which inhibits HER2 and EGFR) has been used since 2007 for metastatic HER2-positive BC [103] and shows efficiency on PFS and/or OS for patients with HER2+ BC in association with capecitabine [104], trastuzumab [105], or Letrozole [106]. The gene discussed is ERBB2; the disease is breast cancer.