Evidence suggests the pathophysiological role of proinflammatory cytokines, especially TNF-α, in the development of major depressive disorder and neuroaxonal injury (Kita, Tanaka et al., 2000; Raison, Borisov et al., 2010; Kaster, Gadotti et al., 2012; Chio, Chang et al., 2013). The gene discussed is TNF; the disease is major depressive disorder.