The C-C chemokine receptor CCR4 has an essential role in the development of autoimmune encephalomyelitis and its expression is required on dendritic cells, not on T cells The CC chemokine receptor 4 (CCR4) and its ligands, CCL17 and CCL22, contribute to the pathogenesis of allergic responses and infectious and autoimmune diseases by directing T lymphocyte trafficking to inflammatory sites.