The first study of intensive care unit (ICU) patients with or without infection/systemic inflammatory response syndrome (SIRS) revealed that IL-8 concentrations were significantly associated with delirium in infected patients, whereas the anti-inflammatory cytokine IL-10 and amyloid β1-42/40 were associated with delirium in non-infected patients [19]. This evidence concerns the gene CXCL8 and systemic inflammatory response syndrome.