Antidepressant pharmacotherapies are known to reduce the synthesis of peripheral pro-inflammatory cytokines and induce the production of anti-inflammatory cytokines such as IL-10, Transforming Growth Factor beta-1 (TGF-β1), and brain-derived neurotrophic factor (BDNF), exerting a significant immunoregulatory effect in patients with depression [85,86]. The gene discussed is BDNF; the disease is depressive disorder.