In particular, Ghazavi et al. investigated the serum levels of interferon IFN-γ, IL-5, IL-8, Il-9, IL-17, and TGF-β in mild and severe COVID-19 patients vs. healthy controls, finding that only TGF-β levels were significantly higher in the COVID-19 groups [11]. Here, TGFB1 is linked to COVID-19.