PTGS2 and neoplasm: On the one hand, ω-3 PUFAs can inhibit the activity of COX-2 and reduce the production of PGE2, thereby inhibiting the proliferation, invasion, and angiogenesis of tumor cells; on the other hand, ω-3 PUFAs can compete with ω-6 PUFAs to bind to COX-1 to produce PGE3, which can significantly inhibit the proliferation, invasion, and angiogenesis of tumor cells.