We found that RANKL stimulation in OA and RA synovial fibroblasts decreased miR-548aj-3p and miR-3127-3p expression and enhanced interleukin-1 beta (IL-1β), interleukin-6 (IL-6), and matrix metalloproteinase-13 (MMP-13) production by using quantitative reverse transcription polymerase chain reaction (RT-qPCR) and enzyme-linked immunosorbent assay (ELISA). This evidence concerns the gene MMP13 and rheumatoid arthritis.