The serum levels of remaining six inflammatory cytokines (IL-1β, IL-4, IL-12, IL-17, IL-21, and IL-23) did not show a significant difference between the psoriasis patients and control groups (Figure 2, Supplementary Figures 8–13; IL-1β: SMD = 0.06, 95% CI -0.59 to 0.71; IL-4: SMD = 0.25, 95% CI -0.21 to 0.70; IL-12: SMD = 0.22, 95% CI -0.55 to 1.00; IL-17: SMD = 0.43, 95% CI -0.16 to 1.03; IL-21: SMD = 1.55, 95% CI -0.21 to 3.31; IL-23: SMD = 0.66, 95% CI -0.25 to 1.58). The gene discussed is IL21; the disease is psoriasis.