Five decades after it was revealed as a forgery, the Piltdown man still haunts paleoanthropology. Now, thanks to the disgraced stem cell researcher Woo Suk Hwang, cell biology has a high-profile scandal of its own to live down. Few recent papers in biology have soared as high in acclaim as Hwang's 2004 and 2005 announcements of cloning human embryonic stem cells--or plummeted as fast into infamy with the discovery that they were rank fakes [see "Down in Flames," by Sara Beardsley, News Scan, on page 20].

Embryonic stem cell (ESC) research is no less promising today than it was before Hwang's deceit was revealed; most investigators continue to believe that it will eventually yield revolutionary medical treatments. That no one has yet derived ESCs from cloned human embryos simply means that the science is less advanced than has been supposed over the past two years.

Still, Hwang has badly sullied the reputation of a field that already has more than its share of political and public relations problems. Some longtime opponents of ESC research will undoubtedly argue that Hwang's lies only prove that the investigators cannot be trusted to conduct their work ethically, and the public may believe them. This is one more crime against science for which Hwang should be ashamed. (A minor footnote to this affair is our removal of Hwang from the 2005 Scientific American 50 list; see the retraction on page 16.)

In recent years, fabricated data and other fakery have been uncovered in work on materials, immunology, breast cancer, brain aneurysms, the discovery of new elements and other subjects. As the volume of publication rises, fraud will probably rise with it. Because of the growing financial ties between university researchers and corporations, not to mention the jockeying for leadership among nations in high-stakes areas such as stem cells, some scientists may feel more pressure to deliver results quickly--even if they have to make them up.

These affairs have something in common with the Jayson Blair and Stephen Glass scandals that not long ago rocked mainstream journalism: all these scams exploited the trust that editors extend to submitting authors. The editors and peer reviewers of scientific journals cannot always verify that a submitted paper's results are true and honest; rather their main job is to check whether a paper's methodology is sound, its reasoning cogent and its conclusions noteworthy. Disconfirmation can only follow publication. In that sense, the Hwang case shows how science's self-correcting mechanism is supposed to work.

Yet it is important not to brush off the Hwang case as a fluke without considering its lessons for the future. For instance, Hwang's papers had many co-authors, few of whom seem to have been party to the cover-ups. But what responsibilities should co-authors have for making sure that papers bearing their names are at the least honest?

We should also think hard about whether Hwang's deceit went undetected for months because so many scientists and science journalists wanted to believe that ESC research was progressing rapidly, because that would hasten the arrival of miraculous therapies and other biomedical wonders. Extraordinary results need to be held suspect until confirmed independently. Hwang is guilty of raising false expectations, but too many of us held the ladder for him.