In addition, the upregulation of PBK, BIRC5, PLK1, and EZH2 was also validated in HCC tissues (Xiao et al., 2019; Yang et al., 2019; Tian et al., 2020; Huang et al., 2021; Lin et al., 2021; Peng et al., 2021). The gene discussed is PLK1; the disease is hepatocellular carcinoma.