Microarray analysis showed up-regulation of a number of pro- and anti-inflammatory cytokines, including IL-1α, IL-2, IL-3, IL-5, IL-8, IL-9, IL-10, IL-12A, IL-13, IL-15, IL-18, IFNγ, and lymphotoxin α (TNF superfamily member 1) in the BA10 of psychotropic drug-free persons with a history of MDD [61]. Here, IL9 is linked to major depressive disorder.