CXCL8 and endometriosis: The peritoneal fluid of endometriosis is characterized by the enhanced concentration of inflammatory mediators like IL-1, IL-6, IL-8, TGF-β, TNF-α, VEGF, cyclooxygenase-2 (COX-2), and monocyte chemoattractant protein 1 (MCP-1) [61,62].