RANTES/CCL5 (regulated upon activation, T cell expressed and secreted) is a member of the "C-C" or β family of chemokines that induce inflammation and are associated with a number of inflammatory disorders. It functions as one of the natural ligands for the chemokine receptor chemokine (C-C motif) receptor 5 (CCR5), and it suppresses in vitro replication of the R5 strains of HIV-1, which use CCR5 as a coreceptor. Alternative splicing results in multiple transcript variants that encode different isoforms.