TNF and COVID-19: The severity of COVID-19 is positively correlated to the level of inflammatory cytokines such as interleukins (IL-2, IL-6, IL-7, IL-10), granulocyte colony-stimulating factor (GCSF), interferon gamma-induced protein 10 (IP-10), monocyte chemoattractant protein-1 (MCP-1), macrophage inflammatory protein 1 alpha (MIP-1A) and tumor necrosis factor -alpha (TNF-α).