Our finding demonstrated significant cumulative OR of the HLA-DRB1 Val11 for risk of ACPA-positive RA (ORcumulative 2.86 2.90, p < 0.0001); however, we observed high heterogeneity within studies (I2 =91%) (supplementary Figure 2a). This evidence concerns the gene HLA-DRB1 and rheumatoid arthritis.