PTGS2 and cancer: NF‐κB was overexpressed in almost all cancer cells and mediated multiple signaling pathways to contribute to cell proliferation and to treatment resistance.28, 29, 30 INOS, PTGS2, and, TNF‐alpha, and, IL‐6 are important factors in the NF‐κB pathway.31 Ren et al found that radiation increased NF‐κB activity, while NF‐κB inhibitor enhanced radiation‐induced cell death.