Article History

First Online: 30 May 2017

Change Date: 14 June 2017

Change Type: Update

Change Date: 25 July 2017

Change Type: Update

Change Type: Correction

Change Details: Editorial Note: readers are alerted that the conclusions of this paper are subject to criticisms that are being considered by editors. A further editorial response will follow the resolution of these issues.

Change Details: Editorial Expression of Concern: The editors of Nature Methods are issuing an editorial expression of concern regarding this paper to alert our readers to concerns about interpretation of the data. Multiple groups have questioned the interpretation that single nucleotide changes seen in whole-genome sequences of two CRISPR–Cas9-treated mice are due to the CRISPR treatment. Since the background genetic variation between the control mouse and the CRISPR-treated animals is not known, an alternative proposed interpretation is that the observed changes are due to normal genetic variation. We are in contact with the critics and with the authors to examine this matter further. We will update our readers once these investigations are complete. All the authors do not agree with the journal's decision to issue an editorial expression of concern.

Change Date: 30 March 2018

Change Details: This paper is being retracted because the genomic variants observed by the authors in two CRISPR-treated mice cannot be conclusively attributed to CRISPR–Cas9. The paper was a peer-reviewed Correspondence in the journal. The authors made their observation as part of their work on correction of a gene involved in blindness. The authors used mice of the inbred FVB/NJ strain from the JAX genetic quality control program that were purchased within months of each other and that were not bred in the authors' laboratory. The assumption was that this design was sufficient to control for genetic variation in an inbred strain. Since publication of the work, however, it has been brought to the journal's and the authors' attention that without parental controls or more analysis of genetic background, it is not certain that the variants reported are due to CRISPR treatment ( , , , , ). The study is therefore being retracted to maintain the accuracy of the scientific record. S.H.T. and W.-H.W. agree with the retraction. K.A.S., D.F.C., A.G.B. and V.B.M. do not agree with the retraction. All authors note that there is very little whole-genome sequencing data on the effects of CRISPR treatment in vivo. The question of whether CRISPR has effects on the in vivo genome will require further study; the authors are carrying out follow-up studies using whole-genome sequencing.

Competing interests

: The authors declare no competing financial interests.