Nat. Immunol. 12, 959–965 (2011); published online 4 September 2011; corrected after print 17 November 2011.

In the version of this article initially published, the sensor DDX41 was suggested to recognize Z-form DNA in addition to conventional B-form DNA. Although GC-rich DNA has the potential to adopt a left-handed Z-DNA conformation under conditions of high salt or ethanol, whether the GC-rich oligonucleotides used the original study actually adopted the Z-DNA conformation remains uncertain. Therefore, the article has been corrected throughout to reflect whether poly(dA:dT) or poly(dG:dC) was used to stimulate cells. The errors have been corrected in the HTML and PDF versions of the article.