Taking into account that chemotherapy and radiotherapy can induce COX-2 activity in GBM cells with PGE2 synthesis which in turn causes overexpression of immunosuppressive cytokines and inhibits T cell infiltration and proliferation, several findings suggest that the conventional treatment-induced immunosuppression can be counteracted by NSAIDs such as diclofenac, NS398, celecoxib [32–34]. The gene discussed is PTGS2; the disease is glioblastoma.