Previous studies have shown that seven mRNAs in the mRNA risk signature can act as oncogenes to promote HCC progression, including PPM1G [39], PHOSPHO2 [40], YBX1 [41], PSRC1 [42], UCK2 [43], EZH2 [44], and CDCA8 [45]. This evidence concerns the gene PPM1G and hepatocellular carcinoma.