Eotaxin is a recently discovered chemokine characterized by its high chemotactic selectivity for eosinophils. The position of the four cystein residues in Eotaxin places it in the C-C family of chemokines, along with chemokines such as RANTES, MCP-3, and MIP-1 alpha. The human Eotaxin is a 8.3 kDa protein containing 74 amino acid residues.