Altered numbers and/or function of CD19+CD24hiCD38hi B cells are associated with the pathogenesis of various autoimmune diseases, including systemic lupus erythematosus (SLE) [10, 15], rheumatoid arthritis (RA) [14], ulcerative colitis [11], and ankylosing spondylitis [24]. The gene discussed is CD19; the disease is rheumatoid arthritis.