It was reported that METTL3 exerted tumour promoter function in the development of AML with the methylation catalytic activity.92, 93 Knockdown of METTL3 led to a proliferation defect in AML cells, whereas overexpression of METTL3 rescued the proliferation defect, but inhibited myeloid differentiation of haematopoietic stem/progenitor cells (HSPCs).92, 93 Further investigations showed that the expression patterns of METTL3 and METTL14 were much more abundant in AML cell lines. The gene discussed is METTL3; the disease is acute myeloid leukemia.