DRD4 and major depressive disorder: It is activated by EGF and promotes the activation of inflammatory cytokines in cells.[43] In MDD, PTGS2 can inhibit the expression of 5-HT and promote the elevation of IL-1β, IL-6, and TNF, which is significantly reversed after administration of PTGS2 inhibitors.[43] Through WGCNA and GSEA, we further identified 3 core genes for XJZT treatment of MDD, including AKT1, D(4) DRD4, and KMO, which mainly involve ubiquitin-mediated proteolysis, AA metabolism, and Huntington disease.