Also, the level of adenosine was significantly lower in severe compared to moderate cases (26 ± 2.7 vs. 41 ± 4; respectively) (Figure 3A,B), while the levels of IL-10 and TGF-β were higher in COVID-19 patients than in healthy subjects, and the levels of these cytokines were significantly higher in severe cases than moderate cases (Figure 4A–D). Here, IL10 is linked to COVID-19.