CCL2 and complex regional pain syndrome: A key feature of CRPS is neurogenic inflammation, and in fact in the study of Orlova et al., 14 differentially expressed miRNAs in patients with CRPS correlated with inflammatory and immune related markers, including vascular endothelial growth factor (VEGF), interleukin1 receptor antagonist (IL1Ra) and monocyte chemotactic protein-1 (MCP-1).