To explore the expression of the major m6A-modifying enzymes in ESCC, including METTL3, METTL14, WTAP, FTO, ALKBH5, YTHDF1 and YTHDF2, we first queried the published clinical data sets TCGA (The Cancer Genome Atlas), and found that mRNA expression of METTL3, WTAP, YTHDF1 and YTHDF2 was significantly increased in ESCC tissues compared to that in normal tissues (Figure 1A). This evidence concerns the gene WTAP and esophageal squamous cell carcinoma.