Similarly, prostaglandin-endoperoxide synthase 2 (PTGS2, also known as cyclooxygenase-2), is mainly expressed by glioma cells, macrophages and microglia surrounding areas of tumor necrosis and, through the release of prostaglandin E2, induces GBM cell proliferation and invasion, angiogenesis, immune suppression, and immune evasion [62]. Here, PTGS2 is linked to central nervous system cancer.