CD4 and rheumatoid arthritis: We previously demonstrated that the promoter of this gene is differentially methylated in RA (using both 450K array and direct bisulfite sequencing, as shown in Supplementary Figure S1) early in the disease process [39] and used public transcriptomic data in total CD4+ T-cells (between HC and RA) and immunoassays (performed in house on serum samples) to show that de-methylating the DNA in early RA could be indirectly associated with higher expression (mRNA levels) and higher protein released in the serum (ELISA) [39].