Jeremy and Caroline Theerman were told that their son had only a few months to live. So Jeremy did what any father would do, he cut a piece of himself out to save his kid.

There are, naturally, details to this story.

Tristan Theerman was diagnosed with a rare liver disease at just a couple weeks old. Without a liver transplant, doctors told Jeremy and Caroline, Tristan would die.

Tristan, who was suffering from biliary atresia, was put on a donor-recipient list. After four weeks, though – even with Tristan having a “priority status,” there was still no donor. Tristan’s donor coordinator got a call from the Children’s Hospital, who said something had to be done, or the boy would be dead within 72 hours.

“The options were pretty stark. If you don’t do it, your kid has a pretty good chance of not pulling through,” said Jeremy. “So you just do it. I had no hesitation.” Jeremy went in for the risky surgery to have part of his own liver removed and transplanted into Tristan.

Meanwhile, Tristan had his surgery. The biliary atresia almost immediately began to get better.

When Jeremy finally saw his son at the Children’s Hospital, he said that Tristan “looked like a totally new person — much, much healthier…Before, I was absorbed with what was going on with me, and that brought me back to the big picture.”

Though Tristan will need medication his whole life – he will indeed have a life – thanks to his father.