https://greenmedinfo.com/content/90-...mo-made-pfizerRennet is used as a clotting agent to curdle the milk into cheese, separating the liquid parts of milk from the solids. Pfizer makes a genetically modified rennet, but because of a labeling loophole, cheese containing Pfizer's rennet does not have to be labeled as containing a genetically modified organism.
https://nourishcooperative.com/blog/...ost-us-cheeses