Extrachromosomal DNA: A Trusted Path to Tumor Heterogeneity

Summary: Extrachromosomal DNA (ecDNA) has been suggested as a key factor of tumor heterogeneity at the genomic and transcriptional levels, via unequal segregation and ecDNA hub formation, respectively. In this issue of Cancer Discovery, two studies further expand our understanding of the roles of ecDNA in enhancing tumor heterogeneity at the phenotypic and spatiotemporal levels, as well as in providing a strong selective advantage during tumor evolution. See related article by Montuori et al., p. 2054 See related article by Noorani et al., p. 2078