A pig kidney has been transplanted into a human being for the first time ever, without triggering immediate rejection by the recipient’s immune system, according to Reuters.

This is a potentially major advance that could eventually help alleviate a dire shortage of human organs for transplant.

The procedure done at NYU Langone Health in New York City involved use of a pig whose genes had been altered so that its tissues no longer contained a molecule known to trigger almost immediate rejection.

The surgeons

The recipient was a brain-dead patient with signs of kidney dysfunction whose family consented to the experiment before she was due to be taken off of life support, researchers told Reuters.

For three days, the new kidney was attached to her blood vessels and maintained outside her body, giving researchers access to it.