TLR4 and gastric cancer: TLR4 polymorphisms allow H. Pylori to elude attack from the host innate immune cell, and to survival in gastric epithelium for a long time, leading to chronic inflammation and causing severe gastritis, hypochlorhydria, gastric atrophy, intestinal metaplasia and dysplasia, which are precancerous lesions of gastric cancer [8]–[12].