Lastly, CD21-/low B-cells that are linked to several autoimmune diseases, including rheumatoid arthritis, systemic lupus erythematosus, Sjogren’s syndrome or common variable immunodeficiency (15), were previously reported in a context of B-cell exhaustion and might represent an anergic B-cell population (15–19). Here, CR2 is linked to rheumatoid arthritis.