Article History

First Online: 9 January 2015

Change Date: 14 January 2015

Change Type: Corrigendum

Change Date: 30 April 2015

Change Type: Erratum

Change Details: In the version of this article initially published, the caption for Figure 5 read “Pope Innocent VIII, likely the first patient to undergo parabiosis.” In fact, he did not undergo parabiosis, but a blood transfusion. The caption should have read “Pope Innocent VIII died in a rejuvenation attempt in 1492.” The errors have been corrected in the HTML and PDF versions of the article.

Change Details: In the version of this article initially published, Retrotope Inc. was included in Table 1 in the “Walking dead” category. Nature Biotechnology has since been informed by Retrotope management that the company raised $10 million in seed funding in 2014. Retrotope has been removed from Table 1. The error has been corrected in the HTML and PDF versions of the article.