The following genes were measured but did not differ significantly between control, RA-risk and RA FLS: FOXO4, BCL2L1, GLB1, EFNB1, CD38, NAMPT, SOD2, SIRT1, p53 (online supplemental figure 4), IL6, CDKN1A, CDKN2A, CDK4, MLH1, PMS2, BRCA2 and ERCC2. This evidence concerns the gene CDK4 and rheumatoid arthritis.