Monocyte Chemoattractant Proteins 4 (MCP-4/CCL13) is member of a distinct, structurally-related subclass of CC chemokines. MCP-4/CCL13 is a major chemoattractants for eosinophils, basophils, monocytes, and T lymphocytes. The MCP protein family bind to specific G-protein-coupled receptors, initiating a signal cascade within the cell. Expression of MCP-4/CCL13 mRNA and protein is greater in the sputum, epithelium, submucosal inflammatory cells, and bronchoalveolar lavage fluid of asthmatics than in healthy individuals. Involvement of MCPs has also been demonstrated in renal inflammation and atopic dermatitis. The expression of this protein is also correlated with enhanced inflammatory immune responses during immunotherapy. The recombinant construct corresponds to the “short-chain” of CCL13 spanning amino acids 24 – 98.