The gastric cancer genome is characterized by focal amplification of oncogenes, including receptor tyrosine kinases, such as ERBB2 (HER2), EGFR, ERBB3, VEGF-A, KRAS/NRAS, MET, JAK2, and PD-L1/PD-L2 [36]. The gene discussed is ERBB2; the disease is gastric cancer.