While the miR-506 is repressed in RA synovial tissues and FLSs, miR-506 overexpression inhibits cell proliferation by regulating cell cycle arrest, promotes apoptosis and caspase-3 and -8 activities, as well as decreases the secretion of inflammatory cytokines in RA-FLSs by targetting TLR4. Here, CASP3 is linked to rheumatoid arthritis.