TNF and acute respiratory distress syndrome: Severe COVID-19 patients show an elevated level of pro-inflammatory cytokines including IL-2, IL-7, IL-10, granulocyte colony-stimulating factor, γ-interferon-induced protein 10, MCP, macrophage inflammatory proteins, and tumor necrosis factor-α (TNF-α), and the inflammatory cascade may lead to a cytokine storm, which is a key factor for driving both ARDS and extra-pulmonary organ failure (Li and Xu, 2009; Huang C. et al., 2020).