Similarly, when performing a sub-analysis comparing only ACPA+ RA with controls (Table 1), we could see that the number of cells in both IgG+ and IgA+ double negative (IgD−CD27−) B-cell clusters were significantly increased in ACPA+ RA (cluster 21 p = 0.01 and cluster 31 p = 0.03, respectively). This evidence concerns the gene PRTN3 and rheumatoid arthritis.