CXCL8 and endometriosis: Endometriosis is firstly defined as an inflammatory disease, characterized by the activation of macrophage migration inhibitory factor (MIF), tumour necrosis factor‐alpha (TNF‐α) and multiple interleukins (IL‐6, IL‐8, IIL‐1β) and the up‐regulation of inflammatory biomarkers including monocyte chemotactic protein 1 (MCP‐1) and C‐reactive protein (CRP).18