EGFR and glioma: This report provided a glimpse into the biological functions of extrachromosomal DNA (ecDNA), one type of eccDNA that will be discussed further below.37,38 Oncogene amplifications, such as MYC and EGFR, were found in DMs as well.39–42 A work on drug resistance of glioma made ecDNA obtain great attention in 2014.