Not an immunologist, but one claim that contradicts other published work stands out to me — fn 7 and the assertion that ACE2 isn’t expressed in lung tissue. AC

Not an immunologist, but one claim that contradicts other published work stands out to me — fn 7 and the assertion that ACE2 isn’t expressed in lung tissue. ACE2 has been shown as the target site for SARS-CoV [1] and expressed in particular lung epithelial cells [2] and an important factor in infections with the first SARS-CoV [3]. I wonder whether this nicotinic hypothesis is more important for understanding the transmission and infection modes of the virus, rather than its involvement in acute disease. [1] https://science.sciencemag.org/content/367/6485/1444 https://science.sciencemag.org/content/367/6485/1444 [2] https://www.biorxiv.org/content/10.1101/2020.01.26.919985v2 https://www.biorxiv.org/content/10.1101/2020.01.26.919985v2 [3] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1287568/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1287568/