Nat. Neurosci. 17, 131–143 (2014); published online 8 December 2013; corrected after print 19 December 2013

In the version of this article initially published, the x-axis labels for the sets of graphs in Figure 2f corresponding to astrocyte, oligodendrocyte and neuron molecules consisted of six items, even though there were only five bars. “Red pulp macrophages” was included in error. Also, the Cleveland Clinic affiliation gave the section as the Department of Immunology; the correct affiliation is Neuroinflammation Research Center. The errors have been corrected in the HTML and PDF versions of the article.