METTL1 and acute myeloid leukemia: To investigate the role of METTL1 in AML, we used short hairpin RNA systems to knock down the expression level of METTL1, which included a negative control (shNC) and two independent shMETTL1 (shMETTL1-1: shM1-1 and shMETTL1-2: shM1-2), which showed efficient knockdown of the protein levels of METTL1 in THP-1 and MOLM-13 AML cell lines (Fig. 2A).