Oncogene at last—c-Jun promotes liver cancer in mice

c-Jun, a component of transcription factor AP-1, has been known to play an important role in the control of cell proliferation. It was also suspected to be a critical mediator of tumor promotion. In a recent paper in Cell, Eferl et al. have now provided conclusive evidence that c-Jun expression is critical for induction of liver cancer by a classical protocol of tumor initiation—tumor promotion.