Until last week, leukemia survivor Fengfeng (not his real name) knew almost nothing about the person who saved his life 13 years ago. Holding a bouquet of flowers, Fengfeng spotted a woman in her 40s. He rushed to her and hugged her. He sensed this was the person he had been waiting for.
Thirteen years ago, Fengfeng was a 15-year-old middle school student in Chongqing. He was diagnosed with chronic myeloid leukemia, a type of cancer affecting the blood-forming cells of the bone marrow.
He has no siblings, and half-match transplant techniques using a patient's parent as the donor had not matured yet. So the only hope was to find a close match outside the immediate family, the possibility of which was only one in 100,000.
Doctors found details of Han Lu, then a 32-year-old nurse at a Chongqing dental hospital, in the city's databank for China's marrow donor programme.
On a winter day in 2004, Han's stem cells were transplanted into Fengfeng's body, saving his life. It was the first unrelated donor stem cell transplant to treat chronic myeloid leukemia in Chongqing.
"I always had a wish after the transplant," Fengfeng said. "I wanted to say 'thank you' to my donor face to face."
However, like others in the same situation, they remained strangers, though they lived in the same city, as international practice and China's stem cell donation rules prohibit donors and recipients from meeting until at least a year after a successful transplant.
Han had long wished to meet Fengfeng, but the boy's health was not stable, making their meeting impossible until now.
They managed to exchange gifts with the help of the Chongqing Red Cross Society.
Fengfeng bought a necklace and a photography book for Han on a trip to Thailand, while Han turned a red cashmere sweater she owned into 25 knitted roses with red straws for stems as a gift for Fengfeng's 25th birthday.
"Cashmere signifies warmth and the red straws look like blood vessels," said Han, who felt gratified when she learned that Fengfeng survived and has had a happy life.
This year, Fengfeng asked the city's Red Cross to help arrange a meeting with his hero. After obtaining Han's consent, Fengfeng's dream came true.
According to Huang Gangyi, deputy director of the Chongqing databank for China's marrow donor programme, most stem cell recipients are unwilling to go public.
"They don't want others to know that they had the disease," Huang said. "But meetings can help people better understand stem cell transplants and raise awareness about the need for donors.
"Many people have misunderstandings about it, thinking transplants will be harmful to the donor's health."
Last year, China's marrow donor programme had more than 2.3 million potential donors, the Red Cross Society of China said in May. The programme has facilitated more than 6,000 hematopoietic stem cell donations for patients at home and abroad.
Moved by the story of Fengfeng and Han, many people have called Huang in the past week and asked how they can become potential cell stem donors.
Fengfeng had type O blood before the transplant. Eventually, his blood type changed to B, the same as Han's.
"She gave me a second chance at life, and now I have a lifelong friend and a new family member," Fengfeng said.