According to several reports, in this work we have confirmed that phosphorylated cPLA2 and COX-2 are key enzymes during Leishmania infection [14, 23, 30]; in addition, we have shown that PPAR activation by agonists prevents cPLA2 phosphorylation and COX-2, either protein or mRNA expression, during macrophages infection with L. mexicana. The gene discussed is PTGS2; the disease is infection.