In the TCGA_LIHC cohort, 16 of 120 genes were downregulated in HCC tissue rather than in adjacent non-tumor tissue, and 9 of 16 genes, namely, ALDH8A1, C11orf96, CLYBL, EFNB3, ENG, NPC1L1, PIM3, SEC14L2, and SLC8A1, displayed a significant difference (p < 0.05) (Figure 5a and Figure S3). This evidence concerns the gene ALDH8A1 and hepatocellular carcinoma.