A study investigating Interleukin-6 (IL-6), Interleukin-8 (IL-8), and Interleukin-6 Receptor (IL-6R) genetic variations and delirium, found no polymorphisms associated with delirium (Marcantonio et al., 2006; van Munster et al., 2011). The gene discussed is CXCL8; the disease is delirium.