An Editorial in the 8 July 2010 issue of Nature tackled the thorny issue of plagiarism. Editors at an increasing number of publishing houses now have access to CrossCheck, a program that uses iThenticate plagiarism software to compare submitted articles against a database of published articles from 83 commercial and learned society publishers. Clear cases of plagiarism (copying of another's work without attribution or citation) need to be effectively dealt with, but self-plagiarism (reproducing your own work) can be a complex issue, especially for reviews journals.

All editors at Nature Reviews Cancer have access to CrossCheck and use it on every submitted article. CrossCheck produces a report that highlights areas of text that match text from the database. An article is then given an overall percentage plagiarism score. These reports can guide editors as to whether a closer look is needed at a particular Review or Perspective. However, they do not replace the need for common sense, good editorial judgement and the input of referees regarding papers that cover similar ground by the same authors. Although a review article may not have text that is a verbatim copy of a previous review article or paper, it might well contain identical ideas, figures and conclusions to one published by the same authors in a different journal, which has perhaps a slightly different target audience. Is this self-plagiarism? Clearly, in one sense, it is not but with most articles now accessed through the internet, gone are the days when research groups could write several similar reviews for different journals because few researchers had access to a large number of journals in print.

Thankfully, plagiarism of any kind is a relatively rare event at Nature Reviews Cancer and we will strive to keep it that way.