Nature Cell Biology http://dx.doi.org/10.1038/ncb3444 (2016); published online 21 November 2016; corrected after print 20 December 2016

In the version of this Article originally published, the colours of the flow cytometry gates in Fig. 1b were incorrect. The gates labelled 'Erythroid', 'Myeloid', 'Lymphoid' and 'Precursor' should have been coloured purple, red, green and blue, respectively. In addition, the first author of ref. 26 was incorrect and this has now been changed to 'Mosimann, C'. These errors have been corrected in the online versions of the Article and the correct version of Fig. 1b is shown here.