Therefore, the aim of the present study was to evaluate Treg and Th17 cells in the peritoneal fluid of women with and without endometriosis in relation to peritoneal concentrations of Treg- and Th17-related cytokines (IL-6, IL-10, IL-17A, and TGF-β) and chemokines (CCL2, CCL5, CXCL8, CXCL9, CXCL10, and CCL20). This evidence concerns the gene CXCL9 and endometriosis.