Pro-inflammatory cytokines are produced in the gastric mucosa by inflammatory cells activated by chronic Helicobacter pylori (H. pylori) infection. Polymorphisms of these cytokine genes are associated with individual differences in gastric mucosal cytokine mRNA level, which result in differences in gastric mucosal inflammation, acid inhibition and gastroduodenal disease risk in response to H. pylori infection. Although polymorphisms of interleukin (IL)-1B, IL-1RN and TNF-A have been reported to relate well with gastric cancer and peptic ulcer risk, those of IL-2, IL-4, IL-6 and IL-8 genes are unclear. In combined analyses using data from previous studies, we found that the risk of gastric non-cardia cancer development was significantly associated with IL-4-168 C allele (OR: 0.81, 95% CI: 0.69-1.00) and IL-4-590 T allele carrier status (0.61, 0.53-0.73), and IL-6-174 G/G genotype (2Pro-inflammatory cytokines are produced in the gastric mucosa by inflammatory cells activated by chronic Helicobacter pylori (H. pylori) infection. Polymorphisms of these cytokine genes are associated with individual differences in gastric mucosal cytokine mRNA level, which result in differences in gastric mucosal inflammation, acid inhibition and gastroduodenal disease risk in response to H. pylori infection. Although polymorphisms of interleukin (IL)-1B, IL-1RN and TNF-A have been reported to relate well with gastric cancer and peptic ulcer risk, those of IL-2, IL-4, IL-6 and IL-8 genes are unclear. In combined analyses using data from previous stud- ies, we found that the risk of gastric non-cardia cancer development was significantly associated with IL-4-168 C allele (OR: 0.81, 95% CI: 0.69-1.00) and IL-4-590 T allele carrier status (0.61, 0.53-0.73), and IL-6-174 G/G genotype (2.02, 1.31-3.10). In peptic ulcer development, IL-2-330 G and IL-4-590 T allele carriers had a significantly decreased risk (0.37, 0.27-0.50 and 0.58, 0.34-0.99, respectively). Moreover, IL-2, IL-4, IL-6 and IL-8 gene genotypes prevalence differs among popula- tions. The inflammatory cytokine gene polymorphisms (e.g. IL-4 -590 and IL-6 -572 for gastric cancer, and IL-4-590, IL-6-572 and IL-8-251 for peptic ulcer) have a more potent influence on development of gastroduo- denal diseases in Western than East Asian populations. These cytokine gene polymorphisms, as well as those of IL-1B, IL-1RN and TNF-A, may be used to identify groups at higher risk of gastric cancer and peptic ulcer, and those suitable for their prevention by H. pylori eradication therapy in Western populations..02, 1.31-3.10). In peptic ulcer development, IL-2-330 G and IL-4-590 T allele carriers had a significantly decreased risk (0.37, 0.27-0.50 and 0.58, 0.34-0.99, respectively). Moreover, IL-2, IL-4, IL-6 and IL-8 gene genotypes prevalence differs among populations. The inflammatory cytokine gene polymorphisms (e.g. IL-4 -590 and IL-6 -572 for gastric cancer, and IL-4-590, IL-6-572 and IL-8-251 for peptic ulcer) have a more potent influence on development of gastroduo-denal diseases in Western than East Asian populations. These cytokine gene polymorphisms, as well as those of IL-1B, IL-1RN and TNF-A, may be used to identify groups at higher risk of gastric cancer and peptic ulcer, and those suitable for their prevention by H. pylori eradication therapy in Western populations. Pro-inflammatory cytokines are produced in the gastric mucosa by inflammatory cells activated by chronic Helicobacter pylori (H. pylori) infection. Polymorphisms of these cytokine genes are associated with individual differences in gastric mucosal cytokine mRNA level, which results in differences in gastric mucosal inflammation , acid inhibition and gastroduodenal disease risk in response to H. pylori infection. Although polymorphisms of interleukin (IL) -1B, IL-1RN and TNF-A have been reported to relate well with gastric cancer and peptic ulcer risk, those of IL- 2 combined with IL-4, IL-6 and IL-8 genes are unclear. In combined analyzes using data from previous studies, we found that the risk of gastric non-cardia cancer development was significantly associated with IL-4-168 C allele ( OR: 0.81, 95% CI: 0.69-1.00) and IL-4-590 T allele carrier status (0.61, 0.53-0.73), and IL- 6-174 G / G genotype produced in the gastric mucosa by inflammatory cells activated by Chronic Helicobacter pylori (H. pylori) infection. Polymorphisms of these cytokine genes are associated with individual differences in gastric mucosal cytokine mRNA level, which results in differences in gastric mucosal inflammation, acid inhibition and gastroduodenal disease risk in response to H. pylori infection. Although polymorphisms of interleukin (IL) -1B, IL-1RN and TNF-A have been reported to relate well with gastric cancer and peptic ulcer risk, those of IL-2, IL-4, IL- 6 and IL-8 genes are unclear. In combined analyzes using data from previous stud- ies, we found that the risk of gastric non-cardia cancer development was significantly associated with IL-4-168 C allele (OR: 0.81, 95% CI: 0.69-1.00) and IL-4-590 T allele carrier status (0.61, 0.53-0.73), and IL-6-174 G / G genotype (2.02, 1.31-3.10). In peptic ulcer development, IL- 2-330 G and IL-4 -590 T allele carriers had a significantly decreased risk (0.37, 0.27-0.50 and 0.58, 0.34-0.99, respectively). Moreover, IL-2, IL-4, IL-6 and IL-8 gene genotypes prevalence 16,547 the inflammatory cytokine gene polymorphisms (eg IL-4 -590 and IL-6-572 for gastric cancer, and IL-4-590, IL-6-572 and IL- IL-8-251 for peptic ulcer) have a more potent on the development of gastroduodenal in Western than East Asian populations. These cytokine gene polymorphisms, as well as of IL-1B, IL-1RN and TNF-A, may be used to identify groups at higher risk of gastric cancer and peptic ulcer, and those suitable for their prevention by H. pylori eradication therapy in Western populations .. 02, 1.31-3.10). In peptic ulcer development, IL-2-330 Moreover, IL-2, IL-4, IL-6 and IL-8 gene genotypes were significantly decreased in G and IL-4-590 T allele carriers (0.37, 0.27-0.50 and 0.58, 0.34-0.99, respectively) prevalence Different among populations. The inflammatory cytokine gene polymorphisms (eg IL-4 -590 and IL-6-572 for gastric cancer, and IL-4-590, IL-6-572 and IL-8-251 for peptic ulcer) have a more potent on on gastroduo-denal diseases in Western than East Asian populations. These cytokine gene polymorphisms, as well as those of IL-1B, IL-1RN and TNF-A, may be used to identify groups at higher risk of gastric cancer and peptic ulcer, and those suitable for their prevention by H. pylori eradication therapy in Western populations.