The high expression of COX-2 will promote the conversion of AA to PGE2, while the D5Di will (1) knock down the conversion of DGLA to AA and limit the generation of metabolic product, PGE2; and (2) promote the COX-2-catalyzed DGLA peroxidation to form 8-HOA, a novel anti-cancer free radical by-product. Here, PTGS2 is linked to cancer.