A clinical trial including 102 COVID-19 patients and 45 controls from Wuhan, China, showed that the serum IL-10 levels of patients with a critical illness (n = 17) were significantly higher than those of patients with moderate (n = 42) and severe (n = 43) illness; further, the IL-10 levels were positively correlated with the concentrations of serum CRP, indicating the potential of IL-10 as an indicator of disease severity.182 Huang et al.9 also reported the significantly high plasma levels of IL-10 in COVID-19 patients admitted to the ICU compared to those who were not. This evidence concerns the gene IL10 and COVID-19.