When Alex saw a certain Facebook post, he didn’t know it would change his life. It was a picture of Darienne, a young girl with special needs whose mom Melissa—a sister of Alex’s former high school classmate—wrote a heartfelt caption pleading for a kidney for her daughter.

It struck a chord with Alex. Inspired by his own special needs son, Karston, Alex decided to reach out to Melissa and let her know he was interested in becoming a living donor for her daughter.

“I try to do things every day that would make my son happy and proud,” he said. “When making my decision to donate, I thought ‘What if my son needed a kidney?’ I’d want someone to step up and do the same for him.”

But Alex also wanted to give Darienne a new life, free of dialysis.

He began the testing process at the University of Utah Hospital, only days after Darienne’s second family member willing to donate was excluded. So, when Alex learned he was not just a match, but a perfect match for Darienne, the phone call to Melissa was an emotional one. And although this wasn’t his own child or his milestone, there were tears.

The surgery took place in May 2016, and it’s been lifesaving for Darienne, now 16. A stranger before the fateful Facebook post, Alex is now “uncle Alex” and keeps up on Darienne’s progress. On the first anniversary of Darienne’s surgery, Melissa’s Facebook post listed things her daughter has been able to do since her kidney transplant: Go on a cruise, go to school with her peers, spend more time with her family, make friends at school, visit Mexico, drink water, eat salt again, build a strong relationship with uncle Alex!

“Helping a complete stranger is pretty awesome. There are so many people out there who need a donor,” Alex said.