In severe COVID-19 patients (Figure 4B and Table 5), the diagnostic performance was good for IL-6 (AUC = 0.844), fair (acceptable) for IL-18 (AUC = 0.785) and IL-35 (AUC = 0.742), and poor for IL-1β (AUC = 0.604). Here, IL1B is linked to COVID-19.