We previously used mass-spectrometry-based plasma proteomics to define a preoperative delirium multi-protein signature that includes zinc-alpha-2-glycoprotein (AZGP1) and c-reactive protein (CRP) and a postoperative signature of interleukin-6 (IL-6), interleukin-2 (IL-2), and CRP [18]. Here, IL6 is linked to delirium.