The Download: gene-edited pig liver transplants, and AI to fight apartheid

Surgeon Abraham Shaked thinks he has probably carried out more than 2,500 liver transplants. But in December 2023, the team he oversees at the University of Pennsylvania did something he'd never tried before. Working on the body of a brain-dead man, they attached his veins to a refrigerator-size machine with a pig liver mounted in the middle of it. For three days, the man's blood passed into the machine, through the pig liver, and back into his body. This "extracorporeal," or outside-the-body, liver is designed to help people survive acute liver failure.