Purity >95% as determined by SDS-PAGE. Regulated upon activation, normal T cell expressed and secreted (RANTES), also called CCL5, is a chemokine produced by T cells three to five days after T cell activation. RANTES signals through G protein-coupled receptors CCR5, CCR3, CCR1, and through the human CMV-encoded viral receptor US28. RANTES functions to recruit immune cells to inflammatory sites.