TMPRSS2 and COVID-19: A broader cellular protease inhibitor such as alpha-1 antitrypsin (AAT), used to treat severe AAT human deficiency and currently under clinical study for COVID-19 due to its anti-inflammatory potential, has already shown capacity to limit SARS-CoV-2 entry in cells expressing TMPRSS2 (Münch, 2020; Oguntuyo et al., 2020).