Researchers have found that CD4+ T-cells from patients with RA have low levels of EZH2, which downregulates the expression of RUNX1, a key transcription factor for Tregs, ultimately inhibiting Treg differentiation, disrupting peripheral immune tolerance, and exacerbating the inflammatory response in the joints of patients with RA (162). The gene discussed is EZH2; the disease is rheumatoid arthritis.