To elucidate whether METTL3-induced SCLC chemotherapy resistance depends on its methyltransferase function, we constructed METTL3 wild-type (pcDNA3.1-METTL3) and mutant (pcDNA3.1-METTL3-mut, with methyltransferase domain deletion) recombination plasmids [33, 34] (Fig. 2K). Here, METTL3 is linked to small cell lung carcinoma.