pigs have been genetically modified so that their organs can no longer carry retroviruses or have modifications to reduce the chance of rejection. Pig lungs from genetically modified pigs are being considered for transplantation into humans. There is even potential to create chimeric pigs that can carry human organs.

https://en.wikipedia.org/wiki/Genetically_modified_animal#:~:text=Pigs%20have%20been%20genetically%20modified%20so%20that%20their,create%20chimeric%20pigs%20that%20can%20carry%20human%20organs.

David Bennett 57-year-old was Approved for an emergency authorization for the xenotransplantation surgery. A genetically-modified animal heart can function as a human heart.