Oncogenes and senescence: breaking down in the fast lane

Aberrant oncogene expression is the driving force behind the development of all cancers. Consequently, robust tumor suppressive processes have evolved in multicellular organisms to recognize and counteract the malignant potential of individual cells harboring deregulated oncogenes. These processes prevent tumor development by directing cells with inappropriate proliferative signals toward distinct terminal states, including cell death and an irreversible form of cell cycle arrest called cellular senescence While much of the cellular machinery that executes these tumor suppressive functions is known, the "oncogenic signals" that engage this machinery are less understood. In this issue of Genes & Development, Ferbeyre and colleagues