IL-19 plasma and saliva levels were significantly higher in severe COVID-19 patients compared to asymptomatic, or mild/moderate COVID-19 cases after adjusting for patient’s age, male sex, BMI, DM, and COVID-19 severity markers including D-dimer, CRP, and ferritin (Fig. 3A for plasma, P < 0.001; and Fig. 3B for saliva, P < 0.001; Supplementary Table 3). Here, CRP is linked to COVID-19.