In accordance with the observation that B cells from SE + RA patients had significantly higher HLA-DR expression (Fig. 1C), there was a significant correlation between CXCR4 expression on memory CD4+ T cells and the amount of HLA-DR expressed on B cells (Fig. 3C), while HLA-DR expressed on monocytes and dendritic cells was not significantly correlated. This evidence concerns the gene CXCR4 and rheumatoid arthritis.