Article History

Received: 3 June 2015

Accepted: 21 March 2016

First Online: 2 May 2016

Change Date: 28 November 2016

Change Type: Update

Change Date: 2 August 2017

Change Type: Correction

Change Type: Correction

Change Details: The editors of Nature Biotechnology are issuing an editorial expression of concern regarding this article to alert our readers to concerns regarding the reproducibility of the original results. At this time, we are publishing the results of three groups (http://dx.doi.org/10.1038/nbt.3753) that have tried to reproduce the results in the critical Figure 4 in the original paper by Han and colleagues, which demonstrates editing of endogenous genomic loci in mammalian cells. None of the groups observed any induction of mutations by NgAgo at any of the loci or under any of the conditions tested above the sensitivity of the assays used. Similar results have been recently reported by a different group of authors in Protein & Cell (doi:10.1007/s13238-016-0343-9). We are in contact with the authors, who are investigating potential causes for the lack of reproducibility. The authors have been informed of this statement. While the investigations are ongoing, Chunyu Han and Xiao Z. Shen agree with this editorial expression of concern. Feng Gao, Feng Jiang and Yongqiang Wu do not feel that it is appropriate at this time. We will update our readers once these investigations are complete.

Change Details: We are retracting our study because of the continued inability of the research community to replicate the key results in Figure 4, using the protocols provided in our paper. In this figure we report that the Natronobacterium gregoryi Argonaute can efficiently create double-strand breaks and edit the genome of human cells using 5ʹ phosphorylated single-stranded DNA as a guide. Despite the efforts of many laboratories (Protein Cell 7, 913–915, 2016; Nat. Biotechnol. 35, 17–18, 2017; Cell Res. 26, 1349–1352, 2016; PLOS One 12, e0177444, 2017), an independent replication of these results has not been reported. We are therefore retracting our initial report at this time to maintain the integrity of the scientific record. We nevertheless continue to investigate the reasons for this lack of reproducibility with the aim of providing an optimized protocol.

Change Date: 1 August 2017

Change Details: Nat. Biotechnol. 34, 768–773 (2016); published online 2 May 2016; addendum published after print 28 November 2016; retracted 26 July 2017; 10.1038/nbt.3547 We are retracting our study because of the continued inability of the research community to replicate the key results in Figure 4, using the protocols provided in our paper.

Competing interests

: The authors declare no competing financial interests.