Selina Rüecker was working on her thesis in December 2020 in a small village outside Giessen, Germany, when she got a call asking if she wanted to save a life.

Four years had passed since Rüecker had registered for Germany’s blood and marrow donor registry. The voice on the other end of the phone line told Rüecker that she might be a match for a person in need of a stem cell transplant. Shortly before Christmas, she learned that her blood samples had been compared to the recipient’s blood and found to be a match. “It was the best Christmas gift ever to know that I was going to be a donor for someone,” said Rüecker, now 25.

Rüecker wondered who was slated to receive her stem cells. She worried about the recipent after the donation was rescheduled from January 2021 to the end of February because the recipient got sick. After two months of waiting, Rüecker drove to Cologne, the closest city to her home that could process a stem cell donation, laid down in a chair as her stem cells were collected, then got the tiniest snippet of information about the recipient: He was a man over 30 from the U.S.

“That’s it,” said Rüecker, a project engineer in the pharmaceutical industry. “That’s the only information I had for two years.”

An AML Diagnosis and a Stem Cell Donor

Rich Hurst fits the description of a man over 30 from the U.S.; he’s 71 and lives in Seattle. Each year at his physical, his physician would marvel at his health. When he came to see her in October 2020 to report he felt something was off — he’d felt exhausted after working with a chainsaw on his property — she reassured him. “Rich,” she said, “nothing’s wrong with you.”

Nevertheless, she ran some blood tests, which led to her calling him later that night to tell him to go directly to the emergency room. “She said something about me having no platelets,” he said, “and if I cut myself, I could bleed to death.”

Hurst learned he had acute myeloid leukemia with an FLT3 mutation, a particularly aggressive cancer. At an appointment with Janis Abkowitz, MD, the hematologist-oncologist who saw Hurst at Fred Hutchinson Cancer Center, he recalls her estimating he had two months to live without treatment. If he were going to survive, he’d need a stem cell donor.

Hurst’s grown children weren’t a match, so his doctors turned to the Be the Match registry, which facilitates bone marrow transplants worldwide for people whose family members are not biologically suited to be donors. The registry identified a potential donor, a 22-year-old woman in Germany. “When you get that information, it’s pretty overwhelming because it’s the only thing that will save your life,” Hurst said. “Chemo won’t save your life, radiation won’t save your life — nothing will unless you can repopulate your body with healthy stem cells.”

“Biologically Connected Friends”

Guidelines governing communication between donor and recipient are stringent and designed to protect both parties’ privacy while allowing enough time to pass to determine whether the donation was successful. Germany keeps identities anonymous for two years but allows donors and recipients to communicate via messages that don’t share any personal information after a year has elapsed since the donation.

Rüecker received a letter from Hurst soon after that period of time had elapsed.

“It was great to hear he was happy and doing well and that my stem cells were feeling good in his body,” said Rüecker, who wrote back quickly with a letter of her own. She signed it, “Your biologically connected friend.”

They corresponded regularly until March 6, 2023, when Rüecker’s donor organization told her the two years were up. If her recipient wanted to reach out, it was fine by them. By that afternoon, Hurst had emailed her from his home 5,000 miles away in Seattle. He’d had O+ blood before he got Rüecker’s stem cells, but now he was A+ just like her. He now had more genetically in common with Rüecker than he did with anyone in the world; he had even inherited her allergies along with her stem cells. She was simultaneously a complete stranger and like the closest of family members. Hurst had to meet her.

He emailed: What did she think about Hurst and his wife coming to Germany?

Four months later, in July, Rüecker, her mom, her sister and her niece met Hurst and his wife, Kim, at the airport. Hurst cried. Rüecker embraced him. “We hugged each other like it was someone you’ve known for years,” she said.

She took Hurst sightseeing in Frankfurt and threw a party for him in her backyard, inviting her family and neighbors. She lined the perimeter with flags, half German, half American. In the middle was an interlaced German-American flag. Hurst said there was so much food — cheese, pretzels, sausages — that it felt like a wedding. “Everyone came to get to know me and celebrate what Selina had done,” he said.

Now back in Seattle, Hurst emails back and forth with Rüecker regularly, when something special happens or just to ask how she’s doing, and they regularly exchange photos. Next year, Rüecker and her boyfriend hope to visit Hurst on his home turf; they’re planning a trip to Seattle, where Hurst will treat Rüecker like the royalty she is. “What’s really cool about Selina is if you Google ‘Be the Match” in Germany, she’s the poster child,” he said. “She’s actually on the brochures.

“The gift of bonus time is so sweet, especially with this new friend in my life,” said Hurst.

The Be the Match registry is always seeking donors. If you’re interested in joining the registry or learning more, visit

Bonnie Rochman is a staff writer at Fred Hutchinson Cancer Center. A former health and parenting writer for Time, she has written a popular science book about genetics, “The Gene Machine: How Genetic Technologies Are Changing the Way We Have Kids—and the Kids We Have.” Reach her at

This article was originally published November 6, 2023, by Fred Hutch News Service. It is republished with permission.