Inflammatory mediators including interleukin-1β (IL-1β), interleukin-6 (IL-6), interleukin-8 (IL-8), regulated upon activation, normal T cell expressed and secreted [RANTES, or chemokine ligand 5 (CCL5)] and tumor necrosis factor alpha (TNF-α), and chemokines including monocyte chemotactic protein 1 [chemokine ligand 2 (CCL2)] are increased in the peritoneal fluid of women with endometriosis (Table 1) (53–58). Here, CCL5 is linked to endometriosis.