CD4 and psychiatric disorder: The CXC chemokine receptor CXCR3 controls CXCL9, CXCL10, and CXCL11 induced leucocyte trafficking to inflammatory sites (62, 63), and reduced CXCR3 expression on CD4+ T cells and CXCR3+ CD4+ T cell numbers have been found in mental disorders (64, 65).