In an analysis of integrated high-throughput data, a number of circRNAs were shown to be linked to overexpression of miR-181a-3p, an inhibitor of the enzyme O(6)-Methylguanine-DNA methyltransferase (MGMT), which is known to be involved in DNA damage, thereby indicating a link between circRNAs and the progression of HCC through miR regulation [59]. This evidence concerns the gene MGMT and hepatocellular carcinoma.