At the moment, the measurement of SCI for clinical or research purposes is primarily carried out by assessing biomarkers of infection or acute inflammation, mainly C-reactive protein (CRP) or fibrinogen and other acute-phase proteins, white blood cell count, erythrocyte sedimentation rate, or cytokines, such as interleukin (IL)-1β, IL-6, and tumor necrosis factor α (TNFα). Here, TNF is linked to infection.