“Although it started as a point of obscure technical reference back in early 2020 as our ongoing pandemic was still in the early stages of spreading its now-ubiquitous wings, it’s now nearly two years later and debates are still raging about the origins and relevance of SARS-CoV-2’s notorious furin-cleavage site or FCS.”

This is a long but technical article. 

https://www.zerohedge.com/covid-19/quasispecies-origins-sars-cov-2s-enigmatic-furin-cleavage-site