TNF and COVID-19: Finally, pro-inflammatory cytokines, in particular IL-1β, IL-6 and TNFα, which are elevated in patients with COVID-19 induce the loss of normal antithrombotic and anti-inflammatory functions of endothelial cells, leading to dysregulation of coagulation, complement and platelet activation and leukocyte recruitment, explaining the wide range of immunological cells and the wide spectrum of histopathologic alterations.