Further characterization of the pre-GC B-cell compartment, which includes the immature/transitional and naïve B-cell subsets, had shown a slight expansion of the less differentiated CD5− CD38++ CD21het CD24++ immature/transitional B lymphocytes RA patients (1.76 vs 0.89 cells/μL in healthy controls) and in the other 2 more differentiated immature/transitional B-cell subsets: CD5+ CD38+/++ CD21het CD24++ (14.59 vs 5.60 cells/μl in HD) and CD5+ CD38het CD21+ CD24+ (30.14 vs 16.90 cells/μl in HD) (Fig. 3B). This evidence concerns the gene CD5 and rheumatoid arthritis.