Nat. Immunol. 10, 958–964 (2009); published online 16 August 2009; corrected after print 18 September 2009

In the version of this article initially published, two citations were not included. These citations, together with text describing their content, have been added to page 958, column 2, as follows: “As neuronal loss is thought to contribute to the pathogenesis of progressive multiple sclerosis5, and as PARP-1 inhibitors suppress the incidence and severity of experimental autoimmune encephalomyelitis (EAE)36,37, we investigated the function of 15-oxysterols in multiple sclerosis and EAE.” The added references are as follows:

The error has been corrected in the HTML and PDF versions of the article.