Mutations in the tumor suppressor p53 occur in a majority of human cancers. Some gain-of-function (GOF) p53 mutations endow tumor cells with increased metastatic ability, although our understanding of the underlying mechanism remains incomplete. In this issue of , Pourebrahim and colleagues (pp. 1847-1857) develop a new mouse model of osteosarcoma in which a GOF mutant p53 allele is expressed specifically in osteoblasts, while the tumor microenvironment remains wild type for p53, allowing for the study of cell-autonomous functions. In this model, the role of GOF mutant p53 in promoting lung metastasis is shown to be critically dependent on the transcription factor Ets2 and is accompanied by the elevated expression of a cluster of small nucleolar RNAs (snoRNAs).