Katharina Harf was just 13 years old when she found out that her mother, after surviving a bout with breast cancer, had acute leukemia and was in dire need of a bone marrow transplant.
Harf's father, chairman of Coty, Inc., refused to accept the dearth of donors in their home country of Germany and began his own recruitment. After intense efforts, he founded DKMS, a bone marrow matching service.
Now, with a little help from celebrities like Rihanna, DKMS has become the world's largest bone marrow donation site, Tonic reports.
The foundation has come a long way since its creation in 1991.
Though it attracted a staggering 68,000 donors in the first year, Harf's mother lost her battle to the disease. The tragedy further cemented the Harfs' resolve to expand their cause, and in 2004, they introduced the foundation to America.
Tonic spoke to Katharina Harf about her decision to continue the foundation in her mother's memory.
"After having done everything in his power to save my mother, my father said right away that we still needed to save other people's lives -- for her," says Harf. "My mother had told him that if things didn't work out for her, she wanted him to continue saving lives."
Expansion in America proved harder than anticipated, as DKMS' contacts were largely concentrated in Europe. The fortuitous breakthrough came in 2008 when singer Rihanna learned of mother-of-two Lisa Flynn's urgent need for a bone marrow transplant. The star reached out to the public for help.
Turning to PEOPLE.com to voice her personal plea, the singer succeeded in recruiting over 5,000 donors to enlist DKMS' database, and became a key ambassador for the cause. With the aid of Rihanna, who has since inspired other celebrities including Alicia Keys, Halle Berry, and Jennifer Lopez to jump on board, DKMS' database has swelled, and the foundation has become internationally renowned.
"I am so grateful to all of them, since DKMS needs their voices to win the fight against leukemia. I hope many more will join our cause."
In the past year, Harf's celebrity-driven fundraisers have enlisted over 70,000 new donors. Their Linked Against Leukemia Gala held in New York City last spring reunited recipients with their life-saving donors and raised more than $1.8 million for the foundation.