Eotaxin is a CC chemokine that signals through the CCR3 receptor. It is produced by IFN-gamma-stimulated endothelial cells and TNF-activated monocytes. Eotaxin selectively chemoattracts eosinophils and, along with Eotaxin-2 and Eotaxin-3, plays a key role in the regulation of eosinophil recruitment in the asthmatic lung and in allergic reactions. Recombinant Human Eotaxin is an 8.3 kDa protein containing 74 amino acid residues, including the four highly conserved cysteine residues present in CC chemokines.