In RA synovial tissue and RA-FLSs, significantly down-regulated miR-19 [7], miR-92a [8], miR-650 [9] and miR-613 [10] respectively target TLR2, AKT2 and DKK1, inhibiting FLSs proliferation and migration. Here, DKK1 is linked to rheumatoid arthritis.