CXCL8 and endometriosis: Several other cytokines and chemokines have been shown to be present in increased serum levels in patients suffering from endometriosis, of which some of the most researched molecules are CCL5, CCL2, CXCL1, CXCL8, CXCL5, CXCL12 and IL-1, IL-6, IL-8, IL-12 [158].