SCIENCE: Doubts about Johns Hopkins research have gone unanswered, scientist says.

It may be impossible for anyone from outside to know the extent of the problems in the Nature paper. But the incident comes amid a phenomenon that some call a “retraction epidemic.”

Last year, research published in the Proceedings of the National Academy of Sciences found that the percentage of scientific articles retracted because of fraud had increased tenfold since 1975.

The same analysis reviewed more than 2,000 retracted biomedical papers and found that 67 percent of the retractions were attributable to misconduct, mainly fraud or suspected fraud.

Scientists are human, and subject to human flaws and temptations. The scientific method is supposed to overcome those problems, but it does so only so long as people check their work.