Nat. Neurosci. 20, 42–51 (2017); published online 21 November 2016; corrected after print 20 February 2017

In the version of this article initially published, α-MSH was referred to at the beginning of the fourth paragraph of the introduction as an MC4R antagonist. This should have read agonist. The error has been corrected in the HTML and PDF versions of the article.