IFN-γ has been shown to also play a role in stress-induced immune dysregulation (Witek-Janusek et al., 2008) with elevated production of IFN-γ being observed in people with MS with fatigue and depression compared to those with MS and no fatigue (Pokryszko-Dragan et al., 2012). The gene discussed is IFNG; the disease is major depressive disorder.