The MET oncogene encodes the receptor tyrosine kinase (RTK) for hepatocyte growth factor (HGF) and controls genetic programs leading to cell growth, invasion and protec¬tion from apoptosis. Although the definitive role of MET oncogene is yet to be determined in carcinogenesis of gastric cancer, overexpression and amplification of c-Met has been demonstrated in gastric cancer cell lines. In addition, approximately 10-20% of gastric cancer tissues and up to 40% of the scirrhous histological subtype were shown to harbor increased MET gene copy numbers. Importantly, PHA-665,752, a selective c-Met kinase inhibitor showed significant reduction of established tumor mass in mouse xenografts with GTL16, a gastric cancer cell line with >10-fold MET amplification. Another pivotal study showed that gastric cancer cells with MET amplification were extremely sensitive to PHA-665,752 and implicated a potential role of c-Met protein in developing theranostics in gastric cancer. More and more data indicated that c-Met was an important prognostic factor in gastric cancer.