TNF and major depressive disorder: For example, several studies (Cattaneo et al., 2013; Iacob et al., 2013, 2014) reported increased expression of peripheral mRNAs for the pro-inflammatory cytokines interleukin (IL)-1α, IL-1β, IL-6, IL-8, IL-10, interferon (IFN)-γ, migration inhibitory factor (MIF), and tumor necrosis factor (TNF)-α in MDD patients compared with healthy control subjects.