Other works demonstrated the importance of CpG methylation in suppression of ALDH1L1 in several cancer types and cell lines including lung adenocarcinoma, hepatocellular carcinoma (Oleinik et al., 2011), and esophageal squamous cell carcinoma (Chen et al., 2015). Here, ALDH1L1 is linked to esophageal squamous cell carcinoma.