Correction to: Nature Metabolism https://doi.org/10.1038/s42255-020-0198-5, published online 11 May 2020.

In the version of this article initially published, in Fig. 1a, the blunted red arrow from arginine to NO should have been a pointed grey arrow, and the black arrow from arginine to urea should have been a red arrow. The error has been corrected in the HTML and PDF versions of the article.

Fig. 1a
figure 1

Original and corrected