[Targeted epigenome engineering].

Cellular differentiation and homeostasis rely on complex mechanisms to control gene expression, enabling the different cell lineages of an organism to establish and then "memorize" different epigenetic states. The processes that control gene expression are centered on chromatin, a complex of DNA, histone proteins and RNA, whose structure is finely regulated. Targeted epigenomic engineering tools make it possible to interfere with and study these processes, revealing the logic of epigenetic memory mechanisms. This article reviews the main classes of targeted epigenome modification tools and illustrates how they can be used to better understand and modify the epigenome of cells, paving the way for potentially revolutionary therapeutic prospects.