METTL3 and gastric cancer: Recent studies have demonstrated that N6-methyladenosine (m6A) modification of mRNA plays an important role in GC.1–3 METTL3 is upregulated in GC, and it promotes epithelial-mesenchymal transition (EMT) and metastasis of GC by m6A modification of zinc finger MYM-type containing 1 (ZMYM1), leading to ZMYM1-mediated repression of E-cadherin promoter.1 YTH domain-containing family protein 1 (YTHDF1), a m6A reader, plays a crucial role in gastric carcinogenesis.