The entry of any foreign pathogen activates glial cells (astrocytes and microglia) and the over-activation of these cells triggers the release of various neuroinflammatory markers (NM), such as tumor necrosis factor-α (TNF-α), interleukin-1β (IL- 1β), interleukin-10 (IL-10), nitric oxide (NO), COX-2, etc. Various studies have shown the importance of neuroinflammatory markers in the development, diagnosis and treatment of depression (9–11). The gene discussed is TNF; the disease is major depressive disorder.