RANTES (Regulation on Activation Normal T-cell Expressed and Secreted) is a chemotactic cytokine (also known as CCL5), produced by macrophages, epithelial cells, platelets, megakaryoblasts, T lymphocytes and eosinophils. RANTES signals through CCR1, CCR3 and CCR5 receptors and recruits T cells, macrophages, eosinophils and basophils to sites of inflammation. In addition, it stimulates histamine secretion by mast cells, IgE and IgG production by lymphocytes, increases CD80 expression on antigen-presenting cells, and induces activation and proliferation of NK cells.