ALDH2 and neoplasm: Differences in expression and methylation levels were compared between tumor and normal tissues (Figure 1A), which identified nine genes with a negative correlation between expression and methylation levels, including CEL, DGAT2, LCLAT1, and LIPG (hypomethylated and upregulated in tumor tissues), and AGPAT3, AKR1B1, ALDH2, DGKD, and MBOAT1 (hypermethylated and downregulated in tumor tissues), indicating an inhibitory function of methylation in the mRNA expression of those genes.