The present results demonstrate that production of MCP-1, MIP-1α, IL-8 and IL-18 are significantly higher in cell culture supernatants of PBMC from patients with schizophrenia respect to age and gender-matched HC, reinforcing the findings that schizophrenia is accompanied by an activation of the monocyte-macrophage arm of cell-mediated immunity [36]. This evidence concerns the gene IL18 and schizophrenia.