Fig. 1.

Timeline of the historical milestone for the discovery of eccDNA. Research on eccDNA dates back to 1964, when scientists found double minutes (DMs) in embryos and boar sperm. In 1978, DMs was found to be produced by DHFR gene amplification. MicroDNA was discovered in CpG island and 5’end exons in 2012. Over time, DMs were found in both plants and animals, and their name was changed to eccDNA. At first, eccDNA was thought to be present only in tumor cells, until 2017, it was also found to be present in normal cells as well, such as the muscle and blood cells. Then, in 2021, it was discovered that eccDNA occurs in association with apoptosis, bringing researchers a brand-new way to tackle the issue of oncology