Although the release of pro-inflammatory cytokines can contribute to the development of depression-like behavior, TNF-α in particular is receiving considerable attention due to its prominent roles in promoting inflammation and its dampening effects on synaptic plasticity (Khairova et al., 2009; Pribiag and Stellwagen, 2014; Lewitus et al., 2016). This evidence concerns the gene TNF and major depressive disorder.