RANTES is a CC-chemokine that can signal through the CCR1, CCR3, CCR5 and US28 (cytomegalovirus receptor) receptors. It is a chemoattractant towards monocytes, memory T cells (CD4+/CD45RO), basophils, and eosinophils. RANTES also has the capability to inhibit certain strains of HIV-1, HIV-2 and simian immunodeficiency virus (SIV). Recombinant human RANTES is a 7.8 kDa protein containing 68 amino acid residues including the four highly conserved cysteine residues present in the CC chemokines