Classically, it is recognized that the CD5+ B cells could be found in various human tissues being capable of autoantibody production (including rheumatoid factor and anti-ssDNA antibodies) and that the count of CD5+ B cells is expanded in autoimmune diseases such as rheumatoid arthritis and Sjögren’s syndrome (45, 46). The gene discussed is CD5; the disease is rheumatoid arthritis.