In our case-control study, we found significantly (p = 0.043) higher serum levels of TNF-α in MDD patients (47.00±6.60 pg/ml) compared to HCs (28.06±1.07 pg/ml) that indicates TNF-α might be associated with the pathophysiology of MDD (Table 2 and Fig 1). The gene discussed is TNF; the disease is major depressive disorder.