Nat. Med. 20, 741–747 (2014); published online 15 June 2014; corrected after print 25 August 2014

In the version of this article initially published, it was stated that 16K PRL levels are increased in retinopathy, citing reference 10. However, this reference was cited incorrectly, and in fact another paper showed that 16K PRL levels are decreased in diabetic retinopathy. The error has been corrected in the HTML and PDF versions of the article.