Separately, several synovial fluid biomarkers indicative of cartilage injury have been associated with development of arthritis, including the proinflammatory cytokine monocyte chemoattractant protein 1 (MCP-1), also known as chemokine C–C motif ligand 2 (CCL2) [6, 10, 13]. This evidence concerns the gene CCL2 and arthritic joint disease.