The World Stem Cell Hub, an international network for exchanging embryonic stem-cell lines and cloning technology, has been launched by the South Korean government.

Unveiled on 19 October, the hub will be headed by Woo Suk Hwang, who shot to international fame last year for successfully deriving human embryonic stem-cell lines by therapeutic cloning.

The hub's headquarters will be at Seoul National University Hospital, but it will have branches around the world that will train researchers in the technique, provide a bank of cell lines and, where local laws permit, create patient-specific lines. The first branches will be in Britain and California, but Hwang told Nature that he is also talking to researchers in Spain, Sweden and France.

Organizers hope that the first regional branch will be open by January. Each branch will need to find its own funding, but South Korea will establish a non-profit foundation to support the hub's headquarters and the travel of Korean technicians to foreign sites. Gerald Schatten, a reproductive biologist at the University of Pittsburgh, Philadelphia, who will chair the hub's international board of directors, says that the South Korean government is providing about US$50 million.

Western scientists have cautiously welcomed the development. “I'm pleased that the Koreans have been as willing as they have to share their technology,” says Arnold Kriegstein, director of the Institute for Stem Cell and Tissue Biology in San Francisco, whose staff have visited Hwang's lab.

“The Koreans are the experts — no one approaches their efficiency,” adds Stephen Kennedy, a clinical researcher in reproductive medicine at the University of Oxford, UK.

But Kriegstein has ethical concerns about egg donations, and the associated issues of informed consent and record-keeping. He says he is also worried about the technology becoming centralized at such an early stage. Michael German, a diabetes researcher at Kriegstein's institute, agrees: “I would not like to see it become a specialized club where only a limited number of scientists have access to the technology.”