For diagnosis of the COVID-19, the area under ROC curve of CRP was the largest among all cytokines; the preoperative CRP concentration of 3.38 mg/L was the optimal cutoff value for predicting COVID-19 (sensitivity = 92.2 (85.1–96.5)%, specificity = 100%), the positive predictive values = 99.0(96.1–100)%, the negative predictive values = 84.9(72.4–93.2)% (Figure 5 and Supplementary Table 5). Here, CRP is linked to COVID-19.