In longitudinal studies, Souto-Carneiro et al. found an increased proportion of CD27+IgD+ B cells after infliximab treatment in 15 patients with RA [4], whereas Roll et al. found an increased proportion of CD27+ B cells after TNFi in RF-negative RA patients, but not in RF-positive RA patients [9]. This evidence concerns the gene CD27 and rheumatoid arthritis.