> We further show that SARS-CoV-2 is more reliant than SARS coronavirus (SARS-CoV-1) on the TMPRSS2 pathway, and that this difference is due to a furin cleavage

> We further show that SARS-CoV-2 is more reliant than SARS coronavirus (SARS-CoV-1) on the TMPRSS2 pathway, and that this difference is due to a furin cleavage site present in the SARS-CoV-2 S protein. That's interesting, it's a furin cleavage site that the New York "Lab leak hypothesis" article pointed to as suspicious and possibly man-made, though I'm not sure if it's exactly the same.