PTGS2 and cancer: The changes in the morphological appearance, fatty acid composition, PGE2, LTB4 and LXA4 secretion and COX-2, ALOX5, mPGES, PGDS expression noted in LoVo and RKO cells in response to supplementation of different PUFAs indicates that there could occur substantial changes in the way these fatty acids are metabolized by cancer cells that could account for their tumoricidal action.