The IVW method revealed a significant upregulation in the risk for MCP-3 and TNFβ associated with MDD (OR = 0.567, 95% CI = 0.343, 0.938, p = 0.027; OR = 0.571, 95% CI = 0.376, 0.867, p = 0.009). This evidence concerns the gene CCL7 and major depressive disorder.