CXCL13 and rheumatoid arthritis: To sum up, in RA, treatment with either TNF-inhibitors or tocilizumab affects B cell phenotype and the frequency of memory B cell subpopulations in peripheral blood, particularly DN (IgD-CD27-) B cells, but not B cell gene expression or serum levels of CXCL13, sCD23 and BAFF, when comparing baseline with post-treatment follow up.