Sam Reffsin

We also found higher expression of these genes in various comorbidities for severe COVID-19, such as inflammatory disease and tobacco use.

Finally, we found expression of this state in human lung.

We further validated that many factors expressed within this susceptible population directly promote infection with SARS-CoV-2. Some of which, by promoting viral entry.

We applied a retrospective clone tracing method (modified from nature.com/articles/s41587-0…) to rewind time to identify the transcriptional state that infected cells were in prior to infection with SARS-CoV-2. We found a distinct cell state that was highly susceptible to infection.

While amazing work has been done to characterize this variability, previous methods do so after infection has occurred. At this point, the state of infected cells has been rewired by the virus, making it difficult to determine what distinguished infected cells prior infection.