Wettstein, L., Weil, T., Conzelmann, C., Müller, J. A., Gross, R., Hirschenberger, M., et al. (2021). Alpha-1 antitrypsin inhibits TMPRSS2 protease activity and SARS-CoV-2 infection. Nature Communications, 12: 1726. doi:10.1038/s41467-021-21972-0.