CCL2 is a protein involved in chemoattraction and which activates monocytes, activated T cells, basophils, NK cells, and immature dendritic cells primarily due to interaction with CCR receptors on these cells. Additionally, it is believed to reduce IL 12 production by dendritic cells and promote a Th2 phenotype in CD4+ T cells. The role of CCL2 in recruiting monocytes to the sites of inflammation is implicated in the pathology of multiple sclerosis, atherosclerosis, and allergic asthma.