Human Chemokine (C-C Motif) Ligand 5 (CCL5) plays an active role in recruiting leukocytes into inflammatory sites. CCL5 is secreted by many cell types at inflammatory sites and it exerts a wide range of activities through the receptors CCR1, CCR3, CCR4, and CCR5. N-Terminal truncated CCL5/RANTES, Met-RANTES, and amino-oxypentane (AOP)-RANTES exhibit antagonist or partial agonist functions on their receptors. CCL5/RANTES attracts different subtypes of leukocytes into inflamed tissue and intervenes in a wide range of allergic and autoimmune diseases.