PLK1 and hepatocellular carcinoma: While landmark analysis showed that the higher expression levels of ETV4, SOX11, CCNB2, PLK1, BUB1B, and CCNB1 are the worse prognosis, which may be a poor prognostic factor for hepatocellular carcinoma, the higher expression levels of CISH are the better prognosis, which may be a protective factor for HCC prognosis (Figure 13).