title: Focus issue: mechanisms of gene regulation.
abstract: In this Focus Issue of Science Signaling, which complements the Science Special Issue on Gene Regulation (http://www.sciencemag.org/generegulation/), we examine the multilayered mechanisms that control how gene expression is turned on or off. Perspectives in this issue discuss how oncogenic Ras directs the silencing of tumor suppressor genes; how intrachromosomal looping brings enhancers and promoters together to stimulate gene expression; and how the abundance of a transcriptional coactivator affects nuclear receptor-mediated transcription.
authors.forename: John F
authors.initials: JF
authors.lastname: Foley
mesh_terms: D044127:Epigenesis, Genetic; D005786:Gene Expression Regulation; D011401:Promoter Regions, Genetic; D014158:Transcription, Genetic