Previously, scientists have determined that entry of SARS-CoV-2 into cells occurs through a receptor on the cell surface, known as ACE2. But the McMaster-Waterloo team has found that the ACE2 receptor is at very low levels in human lung tissue.
Our finding is somewhat controversial, as it suggests that there must be other ways, other receptors for the virus, that regulate its infection of the lungs, said Jeremy Hirota, co-lead scientist of the team from the Research Institute of St. Joes Hamilton and an Assistant Professor of Medicine at McMaster….
https://uwaterloo.ca/stories/news/researchers-find-clues-sars-cov-2-infection-and-explore-why