TNF and COVID-19: The CpG sites are common targets of viral genome and can be recognized by Toll-like receptors (TLRs) that results in release of pro-inflammatory cytokines including type- I interferon, IL-6, IL-12 and TNF-α (Arpaia and Barton, 2011) those play key role in severe COVID-19 including lung tissue damage (Costela-Ruiz et al., 2020).