Finally, since we and others showed that T cell function is significantly impaired in COVID-19 patients [20–22], we evaluated the basic functionality of the T cell compartment by studying the production of cytokines with anti-viral activity (i.e., IFN-γ, TNF-α, and IL-2) after stimulating peripheral blood mononucleated cells with superantigen Staphylococcal Enterotoxin B (SEB). Here, IFNG is linked to COVID-19.