Ma et al. found that hypermethylation of five CpG loci of the EXO1 gene was related to poor overall survival of HCC patients (Ma et al., 2022), and Yuan et al. found that hypermethylation of two CpG loci of the DDX1 gene was related to poor outcomes (Yuan et al., 2022). Here, EXO1 is linked to hepatocellular carcinoma.