The amplification of RTK genes has been identified in GC, including EGFR encoding epidermal growth factor receptor (EGFR), ERBB2 encoding human epidermal growth factor receptor 2 (HER2, also known as ERBB2), MET encoding Met (also known as c-Met), and FGFR2 encoding fibroblast growth factor receptor 2 (FGFR2), as summarized in Table 1. Here, ERBB2 is linked to gastric cancer.