CCL4 and synovitis: The findings of this review highlight emerging but limited evidence supporting the correlation between US-detected synovitis and a panel of inflammatory cytokines and chemokines such as eotaxin, IL-1RA, IL-8, IP-10, MCP-1, MIP-1α, MIP-1β, PDGF-bb, RANTES, and TNF in in individuals with erosive hand OA.