Many questions still remain unanswered

and many components in the entire metabolic pathways of FU remain unaddressed. For example, DPD deficiency was noted only in a small percentage of patients with severe 5-FU toxicity, leaving a large numbers of patients with an unexplainable molecular basis of toxicity (75). In predicting who will develop toxicity when treated with 5-FU or capecitabine, much more work has to be done (76). In conclusion, while gastric cancer remains a deadly disease, the discoveries of new molecular markers, genetic and epigenetic Inhibitors,research,lifescience,medical alteration, and novel pharmacogenetic traits have helped improve patients care, fostered hope and led new directions of cure. The newest WHO classification of gastric carcinoma is by Inhibitors,research,lifescience,medical far the most comprehensive, describing the morphologic characteristics of each subtype in detail. Hopefully, it will help understand the clinicopathologic entity of each subtype by correlating

its histologic feature with molecular profiling and clinical behavior. It is encouraging that the discoveries of some pharmacogenetic traits have opened the door for individualized medicine, promising the future medicine to be more effective and less toxic because it is based on the molecular fingerprint Inhibitors,research,lifescience,medical not only of each tumor but of each human being. Nevertheless, many challenges remain. Some claims to attempt pharmacogenetic prediction based on the pattern of single nuclear polymorphsim (SNP) may be premature and have not been fully validated. Caution should be exercised as some of claims may be biased Inhibitors,research,lifescience,medical and could lead to harmful consequences (77,78).

Acknowledgments We thank Dr. Rebecca BTK inhibitor Fitzgerald (Hutchinson/MRC Research Center, Cambridge, UK) for kindly providing us the photos in Figure 7, and Dr. Caroline Hughes (Academic Center, Oxford, UK) for kindly providing us the photos in Figures 4 and 5. We also thank Ms. Cheryl Devine for her effort and help in retrieving the cases of gastric carcinoma for photomicrograph. Disclosure: The authors declare Inhibitors,research,lifescience,medical no confict of interest.
Gastric cancer is the second most common Histone demethylase cause of cancer death worldwide (2). The incidence of gastric adenocarcinoma has been declining for decades; however its prognosis remains poor (3). Epidemiological studies have shown that environmental factors such as Helicobacter pylori, diet, and smoking play a significant role in gastric carcinogenesis (4). However, host genetics are thought to contribute as well. For example, although H. pylori infection is known to be associated with an increased risk of gastric cancer, the risk is much higher in subgroups of infected patients who have atrophic gastritis and extensive intestinal metaplasia, suggesting that host genetics influence how often precancerous lesions appear in H. pylori-infected individuals (5).