CD4 and systemic lupus erythematosus: Normalizing results to CD4 and CD8 T cell counts, we observed that EBV-specific CD4+ T cell response was lower in EBV-seropositive SLE patients than in EBV-seropositive healthy subjects (0.1530 (IQR 0.02325-0.3145) vs 1.140 (IQR 0.5235-2.6180) EBV-specific CD4+ T cells/μl EBV-specific CD4+ T cells/μl; P < 0.0001) (Figure 1(b)).