DNMT1 and juvenile idiopathic arthritis: In a study investigating the transcript levels of types DNMT1, DNMT3A, and DNMT3B in peripheral blood mononuclear cells to assess the importance of epigenetic changes in the pathogenesis of JIA, Ghavidel et al. found that DNMT1 and DNMT3A expressions were significantly lower in JIA patients than in healthy control subjects (7- and 5.5-fold, respectively), and this difference was even more significant in the case of young male JIA patients13.