Is there a link between organismal aging and cancer? Pinkston et al. address this question in a worm model of aging and tumor development and find that different signaling pathways implicated in the aging process also control tumorigenesis. Mutant worms with long life spans appear immune to the life-shortening effects of tumors because of enhanced defense mechanisms, including increased apoptosis and decreased cell proliferation within the tumors. Signaling pathways that control longevity may have coevolved with tumor-suppressive mechanisms.