Peripheral blood lymphocytes from 30 patients with DM, 37 patients with other autoimmune diseases (15 cases of SLE, 15 cases of RA and 7 cases of pSS), and 23 healthy individuals were phenotypically analyzed by flow cytometry for their expression of CD19, CD24, and CD38 surface markers. The gene discussed is CD24; the disease is rheumatoid arthritis.