In addition, a four-gene signature including PBK, CBX2, CLSPN, and CPEB3, a four-methylated mRNA signature including BRCA1, CAD, CDC20, and RBM8A, a 5-gene lncRNA signature including RP11-325L7.2, DKFZP434L187, RP11-100L22.4, DLX2-AS1, and RP11-104L21.3, as well as many other polygenic gene signatures have been shown to have prognostic value in HCC (Sun et al., 2019; Wang Y. et al., 2019; Yan et al., 2019). Here, CAD is linked to hepatocellular carcinoma.