Nat. Chem. Biol. 11, 536–541 (2015); published online 21 July 2015; corrected after print 16 September 2015.

In the version of this Commentary initially published, there were several errors in the author list and author affiliations. Bryan Roth was incorrectly listed as “Brian Roth” and his correct affiliations are: The National Institute of Mental Health Psychoactive Active Drug Screening Program (NIMH PDSP), Department of Pharmacology, The University of North Carolina Chapel Hill School of Medicine, Chapel Hill, North Carolina, USA and Division of Chemical Biology and Medicinal Chemistry, UNC Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA. Mathias Frederiksen, from the Novartis Institutes for BioMedical Research, Novartis, Basel, Switzerland, was mistakenly absent from the published author list. These errors have been corrected in the HTML and PDF versions of the article.