van Munster et al. (2011b) observed high levels of IL-8 and cortisol before a delirium onset and high levels of IL-6 and S100 calcium-binding protein B (S100B) in the course of delirium but functional genetic variations in interleukin-6 gene (IL6), interleukin-6 receptor gene (IL6R) and interleukin-8 gene (IL8) were not associated with delirium (van Munster et al., 2011b). This evidence concerns the gene IL6R and delirium.