NOS2 and periodontitis: We demonstrate that a PPAR β/δ agonist, GW0742, exerts beneficial effects in a rat model of periodontitis attenuating (1) NF-κB expression, (2) proinflammatory cytokines production, (3) iNOS and nitrotyrosine expression, (4) apoptosis, and (5) the degree of gingivomucosal tissues in rats subjected to ligature-induced periodontitis.