Acts as a ligand for C-C chemokine receptor CCR2 (By similarity). Signals through binding and activation of CCR2 and induces a strong chemotactic response and mobilization of intracellular calcium ions (By similarity). Exhibits a chemotactic activity for monocytes and basophils but not neutrophils or eosinophils (By similarity). Plays an important role in mediating peripheral nerve injury-induced neuropathic pain (By similarity). Increases NMDA-mediated synaptic transmission in both dopamine D1 and D2 receptor-containing neurons, which may be caused by MAPK/ERK-dependent phosphorylation of GRIN2B/NMDAR2B (By similarity). Monomer or homodimer; in equilibrium. Is tethered on endothelial cells by glycosaminoglycan (GAG) side chains of proteoglycans. Interacts with TNFAIP6 (via Link domain). Processing at the N-terminus can regulate receptor and target cell selectivity (By similarity). Deletion of the N-terminal residue converts it from an activator of basophil to an eosinophil chemoattractant (By similarity). N-Glycosylated. Belongs to the intercrine beta (chemokine CC) family.