Published online 19 December 2005 | Nature | doi:10.1038/news051219-3


Timeline of a controversy

A chronology of Woo Suk Hwang's stem-cell research.

Woo Suk Hwang faces questions.Woo Suk Hwang faces questions.© Empics

Concerns about ethics, errors (accidental or intentional) and possible fraud have dogged the stem-cell researcher Woo Suk Hwang, from Seoul National University in South Korea, since his landmark 2004 Science paper on stem cells from a cloned human embryo. Here describes how events have unfolded from that initial paper - with the most recent events presented first (you may want to read from the bottom-up the first time you read this). Keep checking back for updates over the coming weeks.

31 October 2006

A confident and defiant Hwang takes the stand for the first time in court. The defence denies allegations of fraud and embezzlement, and has prepared a case against the charge of violating the bioethics law for the next hearing. A verdict may be handed down by the end of the year.

12 May 2006

Hwang is indicted today on three charges. The Seoul Central District prosecutor’s office charges him with:<newline/>1) Embezzling KRW2.8 billion (US$3 million). <newline/>2) Committing fraud by knowingly using fabricated data to apply for research funds.<newline/>3) Violating a bioethics law that outlaws the purchase of eggs for research.

21 April 2006

Two women who donated eggs to the South Korean effort to produce cloned human embryos for research file a lawsuit against the state and the two hospitals that collected the eggs. They claim they were not made aware of the potential risks of donation. They are seeking 32 million won ($35,000) in compensation.

Woo Suk Hwang of Seoul National University used more than 2,200 eggs from 119 donors in his failed attempts to clone human embryos. Many women were not told of the risks and a large number have since reported side effects.

20 March 2006

Woo Suk Hwang of Seoul National University in South Korea lost his licence to conduct embryonic stem-cell research on 16 March, and was fired by the university on 20 March. There are now no groups licensed to carry out such research for therapeutic cloning in South Korea,although several are licensed for in vitro fertilization-based human embryonic stem-cell research.The retractions of Hwang’s papers in Science meant that he no longer met the legal requirement for a licence of having at least one publication in embryonic stem-cell science in the past three years.

6 March 2006

Hwang admits ordering researchers to fake data for his 2005 Science paper.

10 February 2006

Schatten is cleared of scientific misconduct by the University of Pittsburgh, but chided for taking so much credit for research in which he was barely involved.

February 2006

A truck driver torched himself to death in Seoul after distributing leaflets calling for disgraced cloning expert Hwang to continue his research.

Hwang is being investigated over a variety of legal matters, including misuse of state funds, fraud in applying for funding based on knowingly faked results, and breaching the country's bioethics law.

8 February 2006

Nature looks at how biologists are regrouping after the Hwang debacle, with features investigating the limited supply of eggs for research and the question of whether we will need therapeutic cloning at all. A main contender in the cloning race, Advanced Cell Technology, says it plans to tread cautiously on the ground left vacant by the collapse of Hwang's claims.

2 Feb 2006

Korea's National Bioethics Committee confirmed rumours about the way Hwang procured eggs. It found that Hwang had forced junior members of his lab to donate eggs, and that he used more than 2,221 eggs in his research rather than the 400 or so he acknowledged using. Thirty-five women's groups plan to sue the government for supporting Hwang's research and neglecting issues related to egg procurement. About one-fifth of the donors, many of whom weren't told of the risks, are now suffering side effects.

31 Jan 2006

Two bioethicists retracted a paper in which they outlined the informed-consent procedures for egg donation that they had devised in collaboration with Hwang (K. W. Jung and I. Hyun Am. J. Bioeth. 6 , W19-W22; 2006).

12 Jan 2006

Science issues an editorial retraction of Hwang’s 2004 and 2005 papers, saying: “Because the final report of the SNU investigation indicated that a significant amount of the data presented in both papers is fabricated, the editors of Science feel that an immediate and unconditional retraction of both papers is needed. We therefore retract these two papers and advise the scientific community that the results reported in them are deemed to be invalid…. Science regrets the time that the peer reviewers and others spent evaluating these papers as well as the time and resources that the scientific community may have spent trying to replicate these results.”

  • The full retraction can be found on Science’s website here .

12 January 2006

Hwang makes his first public appearance since 16 December. In a press conference he says: "I, once again, offer a deep apology to the people and the government for having generated this big confusion and scandal... I ask for your forgiveness. I feel so miserable that it's difficult even to say sorry." He stands by his story that the stem cell lines in his study may have been switched by other researchers, and maintains that the "source technology" behind his studies is valid and can be proved. "I think we can create patient-specific stem cells in six months if sufficient eggs are available," he says. "My life will be spent undoing my wrongdoing." Prosecutors have begun searching Hwang's home and office for their fraud investigation.

10 Jan 2006: Verdict

The Soeul National University investigating committee delivers its verdict: both Hwang's 2004 and 2005 Science papers are based on fraudulent data. But his Afghan hound Snuppy is a real clone.

4 January 2006

Science issues a statement saying all authors have indicated a willingness to retract the 2005 paper. They say the wording of the retraction will only be finalized after the SNU investigation is completed, which is expected next week.

2 Jan 2006

PD Notebook, a Korean investigative news programme, airs a piece that levels further charges against Hwang. According to one of its producers, the programme claims that Hwang coerced a junior team member into donating eggs for research.

29 Dec 2005

The Seoul National University (SNU) team that has been investigating the South Korean researcher reports that there is no evidence that Woo Suk Hwang's stem cells came from patient-specific clones. Last week the investigators said that at least nine of eleven stem-cell lines in Hwang's 2005 Science paper were not what the paper claimed them to be (see 23 December entry below). Now they add that the remaining two lines also do not match the DNA of patients, as they were meant to. Instead they match cells from other, normal embryos created by in vitro fertilization. "Currently, we cannot find stem cells that have identical DNA fingerprint traces with patients and Hwang's team does not have scientific data to prove they did harvest patient-specific stem cells," says Jung-Hye Roe, director of research at SNU, in a press conference.

29 Dec 2005

Science issues a statement saying: "There is no question in our minds that the stem-cell paper published 19 May 2005 by the journal Science needs to be retracted, and we are proceeding swiftly but appropriately in that direction." Science adds that they have not yet received official notification of the SNU investigation results, nor do they have all of the co-authors' signatures on a retraction agreement. They give the authors a deadline of 30 December, after which they say they will move towards an editorial retraction.

23 Dec 2005

A rapid investigation of Hwang's work at Seoul National University delivers a damning initial verdict: large amounts of the data in his 2005 landmark paper on patient-specific stem cells were fabricated. The university's investigating team announces in a televised press conference that the data in the 2005 Science paper came from just two cell lines, not 11 as claimed. This "cannot be some error from a simple mistake, but can only be seen as a deliberate fabrication", the panel says. Hwang says that these two stem cell lines, which are frozen in his lab, were derived from cloned embryos from specific patients. The university is doing tests to validate this.Investigation says Hwang liedKorean scandal will have global fallout.

16 Dec 2005

Science announces that Hwang and Schatten have written to request a retraction of their 2005 paper. Science editor Donald Kennedy says the journal received the letter hours before Hwang's press conference in South Korea (see entry below). Kennedy quoted from the letter during a press conference with reporters: "After analyzing the data, our team concludes the results...could not be trusted... Therefore we are requesting to withdraw the paper." Science says it must wait for the entire research team to consent to the retraction - a process that Kennedy says should take "days or weeks - not months."

16 Dec 2005: Apology and defense

Hwang tells a press briefing that he and his team did create stem cells matched to individual patients, but that there were "mistakes made, human errors, in taking photographs and in the preservation of the stem cells''. Hwang says he will seek agreement from his co-authors to retract the Science paper, and will investigate how the mistakes were made. He adds that his team is thawing some frozen stem-cell lines from the study to authenticate them.

Stem-cell pioneer accused of faking data - UPDATE

15 Dec 2005

Scientific American removes Hwang from his position as a Research Leader of 2005.

15 Dec 2005: Accusation of fake data

News stations across Korea report allegations from one of Hwang's collaborators that the work from May 2005 was based on fabricated data. Roh tells the MBC and two other television stations that Hwang had told him "there are no cloned embryonic stem cells".

13 Dec 2005

Schatten asks Hwang to retract their May 2005 Science paper. Schatten claims he has news of allegations from someone involved with the experiment that make him want his name removed from the paper. According to a release from the University of Pittsburgh, Schatten writes to Science and his co-authors: "My careful re-evaluations of published figures and tables, along with new problematic information, now casts substantial doubts about the paper's accuracy."

A letter from eight scientists, including Ian Wilmut, the cloner of Dolly the sheep, is published in Science calling for validation of Hwang's results: "We encourage Hwang's laboratory to cooperate with us to perform an independent test of his cell lines."

11 Dec 2005: Investigation opened

Seoul National University announces an investigation of Hwang's research, as requested by Hwang himself. The university hospital treats Hwang for stress and exhaustion

5 Dec 2005: Investigation opened

University of Pittsburgh officials say they have opened a preliminary inquiry into the 2005 paper.

4 Dec 2005

Media outlets report that the MBC has apologized for the reporting tactics used in their 22 November programme on Hwang.

Mistake in the 2005 paper

According to Science editors, Hwang contacts them to alert them to erroneous duplications in some images published as part of the Supporting Online Material for the 2005 paper. "We made some unintentional error by using about 4 pictures redundantly," he says. Science determines that the redundant images did not appear in the PDF version of the accepted paper, but were inserted later, and says the mistake does not affect the paper's scientific conclusions.

1 Dec 2005: Accusation of mis-matched DNA

The MBC challenges the credibility of Hwang's data. Pursuing a tip-off, MBC gets five samples of patient-specific cell lines from Hwang and sends them, together with corresponding tissue samples, to an independent lab for DNA analysis. The programme reports that the DNA in one cell line does not match the tissue sample as it should. There are many possible explanations for MBC's findings, such as contamination. But the mismatch also raises the possibility that the embryonic stem-cell lines were not cloned from the stated patients. Hwang stands by his science.

According to Science, Moon Il Park, Director and Chair of the Institutional Review Board (IRB) on Human Subjects Research and Ethics Committees at Hanyang University Hospital, reveals to them the results of an investigation by the hospital IRB and Seoul National University IRB. It finds that: "1) two researchers under Dr. Woo Suk Hwang's supervision donated oocytes voluntarily without any coercion and 2) approximately US$1,445 was paid for direct expenses." This was not illegal or in violation of the Helsinki Guidelines of 1964, which prohibit coercion of research subjects. Park also told Science: "We strongly believe that the identified concerns have no impact on the validity of the scientific conclusions."

24 Nov 2005: Admission of payments for eggs

Hwang admits that his stem-cell research used eggs from paid donors and junior members of his team. He resigns from his official positions, saying he will continue his research.

22 Nov 2005

Seoul-based Munhwa Broadcasting Corporation (MBC) aired an investigative news programme showing further evidence that Hwang used eggs from junior members of his lab - the PD Diary program was called "The Myth of Hwang Woo-suk and Suspicions over Eggs."

21 Nov 2005

Sun Il Roh, a fertility expert at MizMedi Hospital in Seoul and a co-author of the landmark paper, admits that 20 eggs he procured and gave to Hwang for his 2004 study were paid for. Roh, a co-author on the 2005 paper, insists that Hwang did not know this.

12 Nov 2005

Schatten publicly cuts all ties to Hwang and his team at Seoul National University.

Mistake in the 2005 paper

The 2005 paper's authors provide Science with corrections to data in the paper's table 2, which are not thought to significantly alter the work's conclusions. The corrected table is published.

11 Nov 2005

According to Science, Schatten tells them he has stopped working with Hwang, because he believes Hwang misrepresented facts about consent issues related to the 2004 paper. Science asks Hwang to inform them of any concerns regarding his research. Hwang says he is looking into the matter.

10 Nov 2005

According to Science, Gerald Schatten, a biologist at the University of Pittsburgh and co-author of the May 2005 Science paper, alerts them to Korean press reports alleging that researcher Sun Il Roh has illegally traded ova. Schatten reassures Science that "none of the oocytes used in Professor Hwang's '04 or '05 Science papers were obtained from reimbursed women donors."

October 2005

Hwang resumes research, ending his voluntary suspension of activities.

19 Oct 2005

South Korea's government launches the World Stem Cell Hub, an international network for exchanging embryonic stem-cell lines and cloning technology. Hwang is to be its head.

3 Aug 2005: Cloned dog

Hwang and colleagues announce the first cloned dog - Snuppy, an Afghan hound (Lee B. C. et al. Nature 436 , 641; 2005). Some scientists hail his birth as a feat of ingenuity and perseverance, others question its value.

19 May 2005: Landmark paper

Hwang's team at the Seoul National University in South Korea reports it has established 11 embryonic stem-cell lines derived from the skin cells of individual patients (W. S. Hwang et al. Science 308 , 1777-1783; 2005). The experiment is hailed as a huge step towards the medical use of person-specific cell lines. It also backs up the embryo-cloning claims in the team's February 2004 paper.

13 Jan 2005

The South Korean government approves Hwang's embryonic stem cell research. It is the first approval issued under the nation's new bioethics law.

1 Jan 2005

South Korean bioethics law comes into effect.

22 May 2004

The annual meeting of the Korean Bioethics Association calls on Hwang and a review board to answer questions about funding sources and the recruitment of egg donors. The association wants the National Human Rights Commission, an independent investigative body funded by the government, to pursue the case. But the commission's bioethics task force was not intended to investigate specific research projects.

May 2004: Ethical questions

Questions are raised about ethical practices in Hwang's work after investigations by Nature. It appears that some of the eggs may have come from junior members of the research team. This is potentially problematic because obtaining human eggs is painful and risky. Hwang denies any wrongdoing, but says that he will suspend his research until a new national bioethics law comes into effect in the new year.

February 2004

Biologists say that the South Korean breakthrough has alerted Western researchers to the pace of scientific and technological progress in East Asia. Hwang and colleagues attribute their success to a supportive cultural environment, well-funded laboratories, and legislation permitting human embryos to be cloned for research. Also critical to the researchers' success was their collection of 242 human eggs from 16 female volunteers.

12 Feb 2004: Landmark paper

Woo Suk Hwang from Seoul National University in South Korea and colleagues announced that they have cloned 30 human embryos and harvested stem cells from one of them (W. S. Hwang et al. Science 303 , 1669-1674; 2004). The work makes headlines worldwide, as a step towards stem-cell therapies for diseases such as Parkinson's. Other groups have claimed to clone human embryos, but the supporting evidence has been sketchy. This success will also need further supporting evidence.