 Specific changes mutation in oncogens, LOH of tumor suppressor genes, deletion or insertion, different for intestinal or diffuse type gastric cancer, were described. Most of these pre-malignant changes happened on a background of long lasting chronic inflammation, following the cascade of atrophy, intestinal metaplasia, and dysplasia. Genetic syndromes are rare and families clustering of gastric cancer are usually attributed to common H. pylori infection. A family syndrome of gastric cancer due to germ-line mutation in E-cadherin has been described, and gastric cancer may be part of Lynch syndrome HNPCC. Mutations and polymorphism of IL-1b and TNFa have been described in first degree relatives of gastric cancer patients, and considered predictive factors for cancer. 