Eotaxin-3, also named CCL26 or SCYA26, is a novel human CC chemokine. The eotaxin subfamily of CC chemokines consists of eotaxin-1/CCL11, eotaxin-2/CCL24 and eotaxin-3/CCL26. Eotaxin-3/CCL26 has been shown to be expressed by several different cell types, including basophils, dendritic cells, smooth muscle cells, epithelial cells and fibroblasts. Interleukin (IL)-4 is the main inducer for eotaxin-3 expression, whereas eotaxin-1 is up-regulated by IL-4 and the proinflammatory cytokine tumour necrosis factor (TNF)-α. Eotaxin-3 is expressed in vascular endothelial cells and human dermal fibroblasts after IL-4 and IL-13 stimulation, and this is dependent upon the IL-4-/IL-13-specific transcription factor, signal transducers and activator of transcription (STAT)-6. Eotaxin-3 is expressed on the surface of IL-4-stimulated endothelial cells and promotes eosinophil transmigration. Eotaxin-3/CCL26 induces calcium flux in eosinophils as well as in CCR3-transfected cells. Eotaxin-3/CCL26 has also been shown to cross-desensitize cells to other CCR3 ligands.