CCL2 exhibits a chemotactic activity for monocytes and basophils. However, it does not attract neutrophils or eosinophils. After deletion of the N-terminal residue, CCL2 loses its attractivity for basophils and becomes a chemoattractant of eosinophils. Basophils and mast cells that are treated with CCL2 release their granules to the intercellular space. This effect can be also potentiated by a pre-treatment with IL-3 or even by other cytokines. CCL2 augments monocyte anti-tumor activity and it is essential for formation of granulomas. CCL2 protein become a CCR2 antagonist when it is cleaved by metalloproteinase MMP-12.