Interlieukin-10 (IL-10, IL-6, IL-8, COX2 (cyclooxygenase-2), VEGF (vascular endothelial growth factor) and tumor necrosis factor α (TNF-α) have been observed to be increased in the peritoneal fluid of endometriosis [34,36]. The gene discussed is CXCL8; the disease is endometriosis.