In contrast, ectopic expression of miR-21 in FLS was found to increase nucleoprotein NF-κB levels and cell proliferation rates, further validating that miR-21 could promote FLS proliferation by facilitating NF-κB nuclear translocation, consequently affecting the function of the NF-κB pathway in RA FLS. Here, NFKB1 is linked to rheumatoid arthritis.