5.3  TNF inhibitors
As previously described, SARS-CoV infection is associated with a downregulation of ACE2 expression coupled with an increased activity of the renin-angiotensin system responsible for lung injury [14].
Moreover, the viral spike protein is able to induce a TNF-α-converting enzyme (TACE)-dependent shedding of the ACE2 ectodomain, crucial for the penetration of the virus into the cell [99]. Since this process seems to be strictly coupled to TNFα production, it has been postulated that the use of TNF inhibitors may be effective in reducing both SARS-CoV2 infection and the consequent organ damage [100]. As a result, a study evaluating adalimumab in COVID-19 infection has recently been registered in the Chinese Clinical Trial Registry (ChiCTR2000030089).