Cover Caption

About the cover: Structure of a nucleosome showing the core histones H3 in green and the histone tail protruding out of the nucleosome outlining the H3K9me2 mark in yellow (1KX5) and superimposed with the H3K9 lysine methyltransferase (2RFI); See article Blancafort et al. on page 563 of this issue.