In line with our previous findings, endometriosis mice exhibited increased mRNA expression of Cox-2 (Fig. 3A; P < 0.01) as well as Tnf-α (Fig. 3B; P < 0.05) in the spinal cord compared with naive and sham-treated animals, and these levels were attenuated following macrophage depletion using liposomal clodronate. This evidence concerns the gene PTGS2 and endometriosis.