Meet some of the world's cleanest pigs, raised to grow kidneys and hearts for humans

Wide-eyed piglets rushing to check out the visitors to their unusual barn just might represent the future of organ transplantation – and there's no rolling around in the mud here.

The first gene-edited pig organs ever transplanted into people came from animals born on this special research farm in the Blue Ridge mountains – behind locked gates, where entry requires washing down your vehicle, swapping your clothes for medical scrubs and stepping into tubs of disinfectant to clean your boots between each air-conditioned barn.

"These are precious animals," said David Ayares of Revivicor Inc., who spent decades learning to clone pigs with just the right genetic changes to allow those first audacious experiments.