This was associated with the fact that HBOT enhanced PO2 in tumor tissues and thus leaded to low expression of HIF‐1α, TNF‐α, IL‐1β, VEGF, MMP9, and NF‐κB. Therefore, hyperbaric oxygen therapy might be a potentially effective therapeutic option and might improve the prognosis for patients with glioma. This evidence concerns the gene MMP9 and glioma.