Lastly, esophageal cancer often exhibits intrachromosomal amplification of MYC, ERBB2, EGFR, RB1, GATA4/6, CCND1, RTK and MDM2 as well as ecDNA-associated amplification of MYC and MDM2 (Testa et al., 2017). This evidence concerns the gene CCND1 and esophageal cancer.