CCL26, also known as Eotaxin-3 and SCYA26, is a small cytokine that is a member of the CC chemokine family. It is only 94 amino acids (aa) in length, with aa 1-23 serving as a putative signal peptide. Human CCL26/Eotaxin-3 has a predicted molecular weight of approximately 11 kDa, and the mature protein only shares 27% aa sequence identity with the mouse ortholog. CCL26/Eotaxin-3 is constitutively expressed at low levels in various tissues including in the heart and ovary. Its expression in upregulated in vascular endothelial cells by IL-13 and IL-4. CCL26/Eotaxin-3 is a selective agonist for CCR3, as serves as a chemoattractant for cells that express CCR3, such as eosinophils, basophils, and Th2 cells. It has also been shown to act as an antagonist for the receptors CCR1 and CCR5. CCL26/Eotaxin-3 plays a role in allergic reactions.