Nature Reviews Genetics (2019) https://doi.org/10.1038/s41576-019-0106-6

Published online 12 March 2019

The originally published article contained an error in Figure 2a: for the left side of the figure part (showing piRNA-directed DNA methylation of mouse transposable elements), DNMT3A/B should have been DNMT3C. The article has now been corrected online.