Correction to: Cell Death and Differentiation: doi:10.1038/sj.cdd.4402315; advance online publication, 18 January 2008

In this article published online and in this issue, an error has been identified in this review, in the description of the findings of reference 55. The correct text should be:

Additionally, it has been reported that MAPK-mediated phosphorylation of serine residues 641 and 643 within the ID of HIF-1α promotes activity by preventing CRM1-dependent nuclear export of the subunit.55