We evaluated the effect of hypoxia and hypoxia-reoxygenation on CEACAM6-mediated H. pylori binding, infection, reactive oxygen species (ROS) generation, and GEC proliferation.<h4>Methods</h4>Hypoxia-inducible factor 1 (HIF1α) and CEACAM6 levels were assessed in various GECs. Here, HIF1A is linked to infection.