DNMT1 and rheumatoid arthritis: However, in the presence of MTX the DNMT1 transcript levels were significantly higher compared to mitogen-stimulated FLS without MTX treatment, both in RA FLS (1.5 ± 0.3 fold, p = 0.04) (Fig. 4b) and OA FLS (2.1 ± 0.4 fold, p = 0.03) (Fig. 4c).