Nature Reviews Cardiology (2018) https://doi.org/10.1038/s41569-018-0027-7 Published online 10 May 2018

The article originally published online contained an error in the figure in which the scale bar was incorrectly associated with a value of 100 µm. This error has been corrected in the HTML and PDF versions of the article to associate the scale bar with the correct value of 1 mm.