Nature Reviews Disease Primers 5, Article number: 45 (2019) https://doi.org/10.1038/s41572-019-0096-x Published online 04 July 2019

In the originally published version of Figure 2, a figure permissions line was omitted in error. The correct figure permission line has now been added to the HTML and PDF versions of the article, stating “Adapted from ref.46, CC-BY-4.0 https://creativecommons.org/licenses/by/4.0/.”. In addition, a typographical error in reference 46 has been corrected.