Nat. Med.; 10.1038/nm.4174; corrected online 20 October 2016

In the version of this article initially published online, the low-zinc diet was incorrectly described as 0 mg per kg body weight (mg/kg) Zn and should be described as 'low-Zn diet; 0 mg Zn per kg of diet (mg/kg)'. The error has been corrected in the print, PDF and HTML versions of this article.