Fig. 2
From: Extrachromosomal circular DNA (eccDNA): an emerging star in cancer
The origin of eccDNA. EccDNA is widely found in all known types of genomic structural sequences and can be created in all life cycles of organisms. Among these sequences, the birth of eccDNA mainly occurs in repetitive sequences, pseudogenic regions and genetic regions. According to the size, eccDNA is divided into four types, namely, spcDNA, telomeric circles, microDNA and ecDNA