From a tweet in the comments:

In this context, it is noteworthy that the FCS site of human ENaC-alpha was characterized at UNC, and thus likely would be known to UNC members of the research team on NIH grant 2R01-AI110964 and the DARPA Defuse proposal

https://twitter.com/_/status/1481705685087920146

It also is noteworthy that the host furin that cleaves ENaC-alpha is expressed in human lung cells and is localized to the Golgi..and thus that FCS site of human ENaC-alpha would be highly relevant for research assessing effects of FCS sites on ability to infect human lung cells.

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How signalling games explain mimicry at many levels: from viral epidemiology to human sociology

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Epithelial Sodium Channels Are Activated by Furin-dependent Proteolysis

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