IL1A and COVID-19: Intriguingly, higher levels of anti-inflammatory molecules [IL-1 receptor type 2 (IL1R2), IL1RA, and transforming growth factor beta (TGF-β1)] and lower levels of IL-18 were also found in monocyte-macrophages from BALFs of severe COVID-19 compared with mild cases, whereas the classical proinflammatory cytokines (IL-1α, IL-1β, IL-6, and TNF-α) were detected at similar levels in the two groups.