For instance, the m6A methyltransferase METTL3 upregulates HBXIP expression by inhibiting the tumor suppressor gene let-7g through m6A methylation, forming a positive feedback loop (HBXIP/let-7g/METTL3/HBXIP) that promotes cancer cell proliferation in breast tumors (Cai et al., 2018). Here, METTL3 is linked to cancer.