The levels of monocyte chemotactic protein-1 (MCP-1/CCL2) [7,8]; regulated on activation normal T-expressed and secreted (RANTES/CCL5) [21]; interleukin-8 (IL-8/CXCL8) [22,23]; and growth-regulated oncogene-α (GROα/CXCL1) [24] are elevated in the peritoneal fluid of women with endometriosis, and their concentrations correlate with the stage of the disease. Here, CCL5 is linked to endometriosis.