Results of immunohistochemistry showed that compared with the control and the NC groups, the expressions of proliferating cell nuclear antigen (PCNA) and intercellular adhesion molecular-1 (ICAM-1) in RA-FLSs were significantly declined in the miR-146a mimic group, but elevated in the miR-146a inhibitor groups (both P < 0.05). The gene discussed is PCNA; the disease is rheumatoid arthritis.