Myc goes global: new tricks for an old oncogene.

Myc, a transcription factor commonly deregulated in tumorigenesis, is thought to mediate its diverse cellular effects by altering the expression of specific target genes. However, it has been difficult to gain a precise understanding of how Myc drives cancer because Myc acts rather weakly at many of its target loci, and it has been reported to regulate as many as 10% to 15% of all cellular genes. A new perspective on this issue has been provided by a recent study that revealed Myc can regulate chromatin structure in a global fashion. These findings suggest actions for Myc that extend beyond the traditional concept of a targeted gene regulator.