A self-described science nerd is the latest American to get an experimental pig kidney transplant, at a crucial point in the quest to prove if animal organs really might save human lives.

The 54-year-old New Hampshire man is faring well after his June 14 operation, doctors at Massachusetts General Hospital announced Monday.

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“I really wanted to contribute to the science of it,” Bill Stewart, an athletic trainer from Dover, New Hampshire, told The Associated Press.

That’s not the only milestone the Mass General team is marking: A pig kidney has kept another New Hampshire man, Tim Andrews, off dialysis for a record seven months and counting. Until now, the longest that a gene-edited pig organ transplant was known to l

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