Nat. Med. 14, 1006–1007 (2008); published online 7 October 2008; corrected 20 October 2008

In the version of this article initially published, US Senator Charles Grassley was referred to as the senior Republican on the Senate's finance and judiciary committees. He is in fact the senior Republican on the Senate's finance committee and a senior member of the judiciary committee. The error has been corrected in the HTML and PDF versions of the article.