Specifically, 5-ALA enhances TNF-α production in glioma cell lines and suppresses prostaglandin E2 (PGE2) production via cyclooxygenase-2 (COX-2) and microsomal PGE2 synthase-1 (mPGES-1), thereby counteracting immune evasion mechanisms in macrophages and promoting an anti-tumor effect [7]. The gene discussed is PTGS2; the disease is central nervous system cancer.