Nat. Genet. 39, 797–802 (2007); published online 27 May 2007; corrected after print 29 August 2007
In the version of this article initially published, our estimate of the rate of formation of spontaneous DNA double-strand breaks (DSBs) in E. coli proportional to DNA content in humans should read that it differs from that of Vilenchik and Knudson (Proc. Natl. Acad. Sci. USA 100, 12871–12876; 2003) by fourfold, not “approximately tenfold” (page 800, line 3, and page 800, line 59). We estimated that there are 0.01 DSBs per E. coli genome replication. Because E. coli has approximately 4.7 × 106 bp per genome (Blattner, F.R. et al., Science 277, 1453–1474; 1997), we estimate that approximately 2 × 10−9 DSBs per bp are replicated, or about fourfold fewer than the estimate of about 0.8 × 10−8 DSBs per bp replicated in human somatic cells (or 50 DSBs per diploid human genome replication) from Vilenchik and Knudson (Proc. Natl. Acad. Sci. USA 100, 12871–12876; 2003). This would bring the number of DSBs per human genome replication down to approximately 13, if it were proportional to that in E. coli. Our error arose from calculating the human equivalent based on haploid, not diploid, human genome size. This error has been corrected in the HTML and PDF versions of the article.