Nature Cell Biology 18, 549–560 (2016); published online 18 April 2016; corrected after print 20 May 2016

In the version of this Article originally published, in the last sentence of the 'Acknowledgements' section, 'Pancreas Biomedical Research Unit' should have read 'National Institute for Health Research Biomedical Research Unit funding scheme through a NIHR Pancreas BRU'. This has been corrected in all online versions of the Article.