A meta-analysis included 14 studies dealing with cytokine concentrations in serum of the first episode schizophrenia patients and reported increased concentration of interleukin IL-1β, IL-6, IL-12, tumor necrosis factor (TNF)-α, transforming growth factor (TGF)-β, interferon (IFN)-γ and soluble IL-2-receptor (sIL-2R) [33]. Here, IL6 is linked to schizophrenia.