In vivo, a multitude of cytokines, including IL‐1β, IL‐1RA, IL‐7, IL‐8, IL‐9, IL‐10, CXCL10, IFN‐γ, and TNF‐α are upregulated in the plasma of COVID‐19 patients, especially in cases with the severe outcome (Huang et al, 2020). This evidence concerns the gene IL9 and COVID-19.