NEW YORK (CBSNewYork) — People run the New York City Marathon for different reasons.

Perhaps the most noble of them all is to save lives.

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That’s exactly why one New Yorker set her sights on the finish line. When she crossed, she got her medal and a huge surprise, CBS2’s Vanessa Murdock reported Thursday.

The journey to the moment began in 2013. You see, that’s when Cliff Sherrill was diagnosed with cancer. His best chance at survival was a bone marrow transplant. Within weeks, doctors found his genetic twin, Burcu Mirza.

“I was a very task-oriented person. We have to be in New York,” Sherrill said. “But after this process, I realize that connection we have as people is the most important thing.”

Mirza registered to be a donor in 2011 after a friend’s 3-year-old son was diagnosed with leukemia. After a bone marrow transplant, he’s now thriving.

“We do have the power to save each other,” said Mirza, of the Upper East Side.

Mirza signed up through DKMS. Jaclinn Tanney told CBS2’s Murdock it’s the largest network of bone marrow donor centers.

“In America, we see every three minutes a new patient is diagnosed with blood cancer,” Tanney said.

Of those, 12,000 need a transplant, but only half will receive one. That’s why Mirza ran 26.2 miles wearing the DKMS logo, to demystify donation.

“It has been five years. I’m a better person. I’m healthier than I was,” Mirza said.

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She told CBS2 she went from couch to running a marathon in four and a half months.

“I felt quite powerful that morning,” she said.

But she admitted by mile 18 she couldn’t feel her legs. The crowd, her family, her cause kept her going and carried her to the finish line.

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“I told myself from the beginning, if this gets tough it’s nothing compared to what a cancer patient goes through,” Mirza said.

Once she crossed that finish line, she felt elated.

“This is going to make a difference,” she said.

What happened next?

“The most surprising thing ever,” Mirza said.

Sherrill was waiting to surprise her. He’d watched her along the route.

They’ve corresponded the old fashioned way for about five years, but Sunday was the first time they met in person.

The sheer joy of of the moment was obvious on both their faces.

“I was a beyond-belief shock,” Mirza said.

CBS2 talked with Sherrill over Skype about meeting the woman who saved his life.

“I’m just the luckiest person int he world. The whole thing was just perfect,” Sherrill said. “That connection has changed my life.”

In Cliff’s words, from his first letter to Burcu back in January 2014, “We never know how much an act of kindness can touch the heart.”

Sherrill said it took two years post transplant to feel like himself again. Now, he’s living the good life and golfing a few times a week.

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For more information on how you can become a bone marrow donor, please click here.