The levels of inflammatory cytokines produced by the adaptive immune system, such as tumor necrosis factor (TNF)-alpha, interleukin (IL)-1β, and IL-6, are elevated in patients with depression, whereas the levels of anti-inflammatory cytokines, such as IL-4, IL-10, and transforming growth factor (TGF)-ß, are decreased [18]. The gene discussed is TNF; the disease is major depressive disorder.