They compared accuracy of Lipopolysaccharide-binding protein (LBP, an acute-phase protein that has been suggested as a marker of infection, because this protein has a role in the innate immune response in binding to lipo-polysaccharide), PCT, CRP, and IL-6 (which has a central role in inducing the synthesis of acute-phase proteins such as CRP, PCT and LBP). Here, IL6 is linked to infection.