To demonstrate the existence of eccDNA in colorectal cancer cell lines (HCT116 and LoVo), we spliced the samples’ eccDNA segments of genes ERBB2, MYCBPAP, TP53I3, EGFR, SLC7A1, and SLC29A1 using IGV 2.8.10 to reveal the complete circular DNA sequences and verified their differential expression by DESeq2 (Fig. 5a). Here, EGFR is linked to colorectal cancer.