CCL2 and systemic sclerosis: The results of 12 studies revealed an association of active disease with an increase in specific cytokines in SSc patients’ serum (TGFβ, IL-1, IL-6, IL-33, IL-4, IL-13, IL-10, MCP-1, IFN-γ, TNF-α, IL-1α, IL-2, and CXCL10).