Abnormalities in the constitutive expression of immunological factors also appear to be involved, in that chronically increased levels of IL-1β, IL-6, IL-8 and TNF-α are positively associated with the severity of the schizophrenia or autism that eventually develops (Maes et al., 2002; Chez et al., 2007; Potvin et al., 2008; Ashwood et al., 2011). Here, CXCL8 is linked to schizophrenia.