Retraction to: Oncogene (2009) 28, 651–661; doi:10.1038/onc.2008.419; published online 17 November 2008

The authors wish to retract this article after examination of the publication raised concerns that the primary real-time PCR data, which underlie several of the figures in the article, may not be accurate. The integrity of all of the data presented therefore cannot be assured.