In patients with major depressive disorder, an increase in the release of proinflammatory cytokines such as interleukin-1 (IL-1) and tumor necrosis factor-alpha (TNF-α) [99], chemokines, and cell adhesion molecules, including α-1 acid glycoprotein, α-1 antichymotrypsin, haptoglobin, human macrophage chemoattractant protein-1 (MCP-1), soluble intercellular adhesion molecule-1 (sICAM-1), and E-selectin [100], has been observed. Here, IL1B is linked to major depressive disorder.