IL6 and major depressive disorder: Elevated plasma concentrations of MMP8 (Figure 5A), active MMP8 (Figure 5B) and the pro-inflammatory cytokines TNF-α (Figure 5C), IL-6 (Figure 5D), and IL-8 (Figure 5E) were observed in both male and female individuals with MDD, accompanied by a decrease in the anti-inflammatory cytokine IL-10 (Figure 5F).