CD4 and systemic lupus erythematosus: As shown in Figure 2A, percentages of CXCR5+ PD1+/CD4+ cells were higher in peripheral blood samples from SLE patients compared with those from normal controls (median 10.94 (25th and 75th percentiles 8.11, 18.32) % vs. 8.17 (7.20, 9.93) %, p<0.01).