CCL2 and spinal cord injury: Matsubara et al. [15] reported that the extracellular domain of Siglec-9 (soluble Siglec-9 [sSiglec-9]) and monocyte chemoattractant protein 1 (chemokine [C-C motif] ligand 2 [CCL2]) induce functional recovery in a rat spinal cord injury (SCI) model.