Additionally, various CC-chemokines (CCL1, CCL2, CCL3, CCL4, CCL5, CCL7, CCL11, CCL13, CCL15, CCL17, CCL18, CCL19, CCL20, CCL21, CCL25, and CCL28), CXCL8, CXCL9, and CXCL10 are also expressed in SFs, STs, and/or fibroblast-like synoviocytes (FLSs) derived from patients with RA (86, 91, 100, 102, 109–121). Here, CCL21 is linked to rheumatoid arthritis.