TGFB1 and COVID-19: Furthermore, a positive correlation was found between the cMono Phenograph clusters specific to severe COVID-19 (clusters 2, 9, 10, and 18) and the soluble immunosuppressive factors IL-10, TGF-β, and VEGFA, as well as with AREG (Fig. 4 I and J), the latter known to be involved in tolerance and tissue repair (32).