Nat. Med. 12, 1294–1300 (2006); published online 22 October 2006; corrected online 27 October 2006, 10 May 2007 and 10 October 2007 and corrected after print 21 July 2008; retracted 7 January 2011

We wish to retract this article because we have been unable to reproduce certain crucial experiments showing validation of signatures for predicting response to chemotherapies, including docetaxel and topotecan. Although we believe that the underlying approach to developing predictive signatures is valid, a corruption of several validation data sets precludes conclusions regarding these signatures. As these results are fundamental to the conclusions of the paper, we formally retract the paper. We deeply regret the impact of this action on the work of other investigators.

Nature Medicine would also like to note that several of the earlier correction dates were either omitted or incorrect. The corrigenda published online 10 May 2007, 10 October 2007 and 21 July 2008 mistakenly omitted the earlier correction date of 27 October 2006. The correction in July 2008 went online on 21 July 2008 but was incorrectly noted in the corrigendum as having gone online 18 July 2008.