Can’t we tell whether the 4% difference between SARS-Cov2 and RaTG13 is responsible for the Furin Cleavage site? If so, that would be a huge connection suggest

Can’t we tell whether the 4% difference between SARS-Cov2 and RaTG13 is responsible for the Furin Cleavage site? If so, that would be a huge connection suggesting GoF and the template coronavirus SARS-Cov2 was based on