Next, we examined the expression of these genes in another cohort using real-time quantitative PCR and the results also showed that both RNA methyltransferases (METTL3, METTL14, and WTAP) and demethylases (FTO and ALKBH5) were significantly downregulated in MDD (Fig. 1b). This evidence concerns the gene METTL3 and major depressive disorder.