Interestingly, some of these proteins, mainly HGF, CXCL9, MCP-3, IL-6, IL-8, CXL10, EN-RAGE, IL10RB, VEGFA, CCL3 and TNF have been also found upregulated in patients with severe COVID-19 (16, 18) and some of them such as HGF postulated as biomarkers for the severe forms of this infection (13, 26, 27). This evidence concerns the gene TNF and infection.