CXCL12 and rheumatoid arthritis: In this regard, we reported previously that CXCL12 enhanced cellular proliferation and expression of cytokines and activation markers by peripheral blood T cells [36,37], and that CCL2, CCL5 and CXCL12 upregulated the expression of cytokines and chemokines by fibroblast-like synoviocytes from RA [38].