Nature 504, 282–286 (2013); doi:10.1038/nature12745

The reduced representation bisulphite sequencing (RRBS) data generated and analysed in this Letter were not originally uploaded to the Gene Expression Omnibus (GEO), but can now be found under accession number GSE52617 (within the GSE52824 super series). As can be seen in this RRBS data, mouse naive pluripotent cells expanded for an extended period (that is, 90 days) in naive 2i/LIF (inhibition of ERK1/2 and GSK3β signalling plus leukaemia inhibitory factor)) conditions, globally lose DNA imprinting.