TNF and COVID-19: In addition, the differentiation of TNF and Th17 cells in the arthropathology of neocoronary pneumonia was examined.[34,35] IL-17 is a pro-inflammatory cytokine produced mainly by Th17 cells and has received much attention for its pro-inflammatory role in diseases including infections and autoimmune diseases.[36] IL-17 binds to its receptor and exerts its biological through MAPK and NF-kB pathways role through MAPK and NF-kB pathways.[37,38] As assessed in patients with COVID-19, excessive activation of Th17 cells leads to increased production of IL-17 cytokines.