For example, melanomas harboring BRAFV600E mutations are selectively sensitive to the BRAF inhibitor Vemurafenib (Flaherty et al., 2010), non-small cell lung cancers (NSCLCs) harboring EGFR mutations to the EGFR inhibitors Gefitinib or Erlotinib (Pallis et al., 2011), HER2 amplified breast and gastric cancers to the HER2 targeting agents Trastuzumab or Lapatinib (Stern, 2012), and KIT and PDGFRA mutant gastrointestinal stromal tumors to Imanitib Mesylate and other small molecule inhibitors targeting mutant KIT and PDGFRα (Antonescu, 2011). The gene discussed is ERBB2; the disease is gastric cancer.