TNF and infection: In their detailed review on CRS in SARS and COVID-19, Ye et al. (2020) discuss that the respiratory epithelial cells, dendritic cells and macrophages, after infection with SARS-CoV, firstly produce low levels of cytokines and chemokines, and in the later stages these cells secrete low levels of the antiviral factors interferons (IFNs) and high levels of proinflammatory cytokines: IL-1β, IL-6, and tumor necrosis factor (TNF), as well as the chemokines CCL-2, CCL-3, and CCL-5 (Figure 1A).