However, the negligible number of somatic mutations in the VH genes of the IgD+CD27- subset and the comparable serological levels of soluble CD27 in RA patients and healthy individuals discounted the possibility that CD27 had been cleaved from the cell surface of pre-switch IgD+CD27+ memory B cells, therefore giving them a false-naïve phenotype. This evidence concerns the gene CD27 and rheumatoid arthritis.