TMPRSS2 and COVID-19: An important point is that the α-1-antitrypsin serine protease inhibitor additionally possesses antiviral and anti-inflammatory properties, including inhibition of TMPRSS2 and ADAM17 enzyme activities, and therefore has been proposed as a possible host protective factor against COVID-19.38,39 The class 1 major histocompatibility complex locus (lead variant rs3094087, P=6.3×10−9) has been associated with a variety of autoimmune, gastrointestinal, blood cell counts, anthropometric, and pulmonary traits.