Histone lysine methylation is regarded as a very stable modification with important functions in epigenetic gene control and for organizing chromatin domains. While more robust modifications of the chromatin template are essential to stabilize epigenetic information, there is now the first evidence for a histone lysine demethylase that reverts an activating methyl mark to the unmodified state (Shi et al., 2004 [this issue of Cell]).
Kubicek, S., & Jenuwein, T. (2004, December 29). A Crack in Histone Lysine Methylation. Cell. Cell Press. https://doi.org/10.1016/j.cell.2004.12.006