CD4 and systemic lupus erythematosus: Upon ex vivo stimulation by plate-bound anti-CD3 and anti-CD28 antibodies for three days (Day 3), the higher proportion of CD4+ IL-23R+ and CD8+ IL-23R+ in all SLE patients remained statistically significant compared to the control group (Figure 1b, d and Figure 2b, d; P = 0.0007 and P = 0.0019, respectively).