Over the past 2 decades, the transmembrane tyrosine kinase (TKI) receptor HER2 (also known as ErbB2 or p185) has been shown to be an effective target for patients with breast cancer, but no treatment to effectively target the HER2 receptor has been particularly successful (Blok, Kuppen, van Leeuwen, & Sier, 2013). The gene discussed is ERBB2; the disease is breast cancer.