Recently, m6A modulators, including “writers” (METTL3, METTL14, WTAP and RBM15), “easers” (ALKBH5 and FTO), and “readers” (YTHDF1/2/3, HuR and HNRNPA2B1), have been considered to be essential for regulation of cancer biology, thus, m6A modification in cancers is gradually becoming the focus of research. This evidence concerns the gene METTL3 and cancer.