Correction to: Cell Death and Differentiation (2015) 22, 1094–1105; doi:10.1038/cdd.2015.24; published online 10 April 2015

Since the publication of this paper the authors have noted an error in title of the paper.

l-Proroline is incorrect. The correct title is shown above and the corrected paper appears in this issue.

The publishers would like to apologize for any inconvenience this may have caused.