PTGS2 and Alzheimer disease: In the present study, none of the diets significantly affected COX-1 or COX-2 levels (Fig. 3A) and the only difference observed was that the levels of cPLA2 contrasted between 3xTg-AD and NonTg animals under the DHA diet (−45% lower in 3xTg-AD, P < 0.05; same diet) (Fig. 3C).