Among inflammatory markers, increased procalcitonin [27], CRP [24, 27, 28, 30–32, 41, 45, 46], and IL-6 [25, 27, 28, 34, 35, 44, 46] were consistently reported to be associated with delirium with the exception of one study that found no increase in IL-6 levels [33]. This evidence concerns the gene IL6 and delirium.