Epigenetic control: slow and global, nimble and local.

The regulation of gene expression involves multiple levels of control, from those that are inheritable to those that are highly responsive to environmental changes. In this issue of Genes & Development, Dong and colleagues (pp. 1159-1173) demonstrate that the dynamically controlled immune response transcription factor NF-kappaB may, in fact, have a role in regulating heterochromatin and gene expression at large distances from its actual target sequences and genes.