Significantly elevated levels of epithelial neutrophil-activating peptide (ENA-78) [10], monocyte chemotactic protein (MCP-1) [11], interleukin (IL)-8 [12], tumor necrosis factor (TNF)-α [13], IL-6 [14, 15], and regulated on activation normal T cell expressed and secreted (RANTES) [12] have all been found in the peritoneal fluid of patients with endometriosis. Here, CCL5 is linked to endometriosis.