Beijing experienced its first snow of this winter on Tuesday, but it had little effect on air traffic to and from the capital, much to the relief of Ye Huifeng, a 36-year-old who is recovering after donating bone marrow stem cells.

Ye Huifeng, accompanied by his wife and daughter in Beijing on Monday, donates his bone marrow, hoping to save the life of a 10-year-old boy in South Korea who has leukemia. Wei Xiaohao / China Daily

The 200 milliliters of stem cells donated by Ye was scheduled to be onboard a 3 pm flight to Seoul, capital of South Korea, where a 10-year-old boy was awaiting a cell transplant to treat his leukemia.

Transplantation of bone marrow helps stimulate growth of the patient's own marrow and restores a leukemia patient's immune system.

Cord blood, donations from relatives and social donors are the three major sources of bone marrow. Experts say only about one-quarter of matches occur among family members. When such a match is unavailable, social donors become the major source of hope.

Ye, a government employee in Qiqihar, Heilongjiang province, said he knew little of stem cell donation until 2006 when he was informed about its need while donating blood. He soon joined the China Marrow Donor Program, China's national bone marrow project that was launched in 2001 and maintains a database of potential donors.

Ye said he didn't expect that a few years later his cells could help save a boy's life since the rate of finding a match among nonfamily members is as low as one in 100,000. However, as soon as he was informed of the match in July, he decided to donate.

Ye's wife Wang Hong said at first she didn't support his decision.

"He told me if I didn't support him, he would regret it every time he recalled that he had a chance to save a child's life and didn't do it," Wang recalled her husband saying.

Ye made his donation on Tuesday at the Air Force General Hospital of the People's Liberation Army in Beijing, following five days of preparatory injections to stimulate his production of stem cells.

The hospital is the only one in the country that handles international bone marrow donations from China.

Ye's donation was the 48th such international stem cell donation from China this year, and the 181st since the program began to upload information to Bone Marrow Donors Worldwide in 2012.

The program's database, which lists samples from nearly 2 million people, has grown into the world's fourth-largest bone marrow registry and the largest of Chinese people, providing hope to Chinese all over the world, as nonfamily matches are most likely to be found among people of the same ethnicity.

The program said 4,612 people have donated their bone marrow. Patients from China and 17 other countries and regions, including the United States, Germany, Switzerland, South Korea and Hong Kong, have received the life-giving cells.

"To collect the cells, circulation of 10,000 ml blood is necessary," said doctor Zhu Peiyu from the hospital. "That amount is equivalent to two times the total amount of Ye's blood."

Such an extraction of stem cells does little harm to the donor's body, Zhu said, but "Ye's immunity will be a little weak after the donation".

Ye will spend one more day at the hospital to recover and depart Beijing for home on Friday.??