In conclusion, in the process of HCl/ethanol-induced gastric ulcer in mice, ROS mediates the activation of MAPK signaling pathway in the gastric tissue of mice firstly, and then the activation of MAPK further activates the expressions of its downstream transcription factors such as NRF2 and NF-κB; ultimately, these factors improve the antioxidant capacity of gastric tissue to suppress the inflammatory response. The gene discussed is NFE2L2; the disease is gastric ulcer.