CXCL8 and endometriosis: Another pro-inflammatory cytokine involved in endometriosis is IL-17A that stimulates the production of pro-angiogenic cytokines, such as IL-8 or IL-1β, and was found in significantly higher concentrations in the peritoneal fluid of patients with minimal-to-mild endometriosis than those with moderate-to-severe endometriosis and without the disease.