Runx2 mRNA expression increased over time as early as 12 h in OA and RA FLS (1-fold without cytokines at 6 h vs. 5-fold at 12 h in OA FLS; 1-fold without cytokines at 6 h vs. 3.6-fold at 12 h in RA FLS) (Figure 3C), which is consistent with the ongoing osteogenic differentiation. This evidence concerns the gene RUNX2 and rheumatoid arthritis.