Macrophage inflammatory protein 1a (MIP-1a), also known as CCR3, belongs to the MIP-1 CC chemokine family. The cytokine is mainly produced by macrophages after stimulation by bacterial endotoxins. In acute inflammatory stage, MIP-1a plays an important role in the recruitment and activation of granulocytes. MIP-1a also stimulates the production of pro- inflammatory cytokines, including IL-1, IL-6 and TNF-a. In normal status, MIP- 1a plays a role in promoting homoeostasis.