Fig. 3.

Current strategies for applying single-cell sequencing to study ecDNA or microDNA. Identification of ecDNA through single-cell whole genome sequencing or circular DNA sequencing can shed light on the heterogeneity of ecDNA copies within cells as well as early oncogene amplification. Furthermore, through the use of multiomics to analyze the impact of ecDNA on transcription or how regulatory elements on ecDNA affect oncogene expression, we can gain a deeper understanding of the role of ecDNA in cancer. Additionally, current research suggests that microDNA production occurs in a cell-type-specific manner and that microDNA has potential applications in cancer diagnosis.