CCL2 and systemic lupus erythematosus: Fifteen of the 27 serum factors, including IL-2, IL-4, IL-5, IL-6, IL-10, IL-12p70, IL-15, IL-17A, bFGF, MCP-1, IP-10, G-CSF, GM-CSF, IL-1RA and TNF-α were significantly higher in SLE LN− and SLE LN+, compared with NC (Fig. 7a, Additional file 7: Table S6).