PTGS2 and chronic gastritis: In addition, chronic gastritis caused by helicobacter pylori causes an increase in gastrin production.[35,71] Another possible mechanism is that HP infection causes inflammation, leading to increased production and activity of cyclooxygenase 2 and uraprostaglandin E2, a biomarker associated with inflammation and associated with CRC risk.[72] Finally, recent studies have shown that certain components of HP cell wall have carcinogenic effects on the colorectal epithelial cells.