Furin cleavage sites are common among coronaviruses, but rare among sarbecoviruses (SARS-like viruses). The presence of the FCS is not determinative, but it's n

Furin cleavage sites are common among coronaviruses, but rare among sarbecoviruses (SARS-like viruses). The presence of the FCS is not determinative, but it's notable, especially since the EHA had proposed in DEFUSE to engineer sarbecoviruses with a human-designed FCS. In that proposal, the WIV would have worked only on collection of novel viruses from nature, with genetic engineering at Baric's lab at UNC. DARPA also declined to fund that proposal, on safety grounds. The Times reported an intelligence leak stating the work continued with other funders at the WIV only, though I haven't seen confirmation beyond that one article. > The investigators spoke to two researchers working at a US laboratory who were collaborating with the Wuhan institute at the time of the outbreak. They said the Wuhan scientists had inserted furin cleavage sites into viruses in 2019 in exactly the way proposed in Daszak’s failed funding application to Darpa. https://www.thetimes.com/uk/article/inside-wuhan-lab-covid-pandemic-china-america-qhjwwwvm0 https://www.thetimes.com/uk/article/inside-wuhan-lab-covid-p...