The c-Myc proto-oncogene is an essential activator of cell proliferation and one of the genes most commonly deregulated in cancer. Although these activities of c-Myc are thought to result from its function as a transcription factor, the scientific literature contains hints that this is not the whole story. A new paper in Nature by Dominguez-Sola et al. reports the surprising observation that c-Myc promotes DNA replication via a nontranscriptional mechanism, and that c-Myc deregulation causes DNA damage predominately during S phase. These results identify c-Myc as a new DNA replication factor and suggest an alternative model for its role in cell growth and tumorigenesis.