POLR2J4 and hepatocellular carcinoma: Previously, it was shown that Homo sapiens of POLR2J4, circ_007993 acts as a tumor promoter in colorectal cancer by promoting cell proliferation via the miR-203a-3p/CREB1 axis.27 Significant upregulation of POLR2J4 was also observed in HBV–HCC cells.