ADAM17 and COVID-19: Part of this protective effect may also be explained by the fact that ICS therapy downregulates the SARS-CoV-2 receptors ACE2 and ADAM17,33 for which inhibition seems to be related to COVID-19 susceptibility and severity.34 Therefore, the ICS-mediated downregulation of ACE2 is thought to be protective, and COPD patients should definitely continue ICS both in general (prior to COVID-19) and after having developed COVID-19.