The proportion of Tregs defined by “CD25 and FOXP3 double positive” (a, c, j, n, o, p, q, t, ac) in PB of RA patients was lower than that of control subjects (REM -2.42, [-3.49 to -1.34]) (I2 = 96%, P < 0.0001) (Fig 4). This evidence concerns the gene FOXP3 and rheumatoid arthritis.