Nature Reviews Genetics 12, 565–575 (2011)

In figure 1Aa of the above article, the imprinting control region (ICR) on the paternal allele of the Airn gene was incorrectly shown as methylated (indicated by a dark grey octagon). This ICR should be shown as unmethylated (indicated by a white octagon). The corrected article is available at: http://www.nature.com/nrg/journal/v12/n8/full/nrg3032.html. The editors apologize for this error.