METTL2A is an S-adenosyl-L-methionine-dependent methyltransferase that catalyzes N(3)-methylcytidine (m3C) modification at position 32 of the anticodon loop in specific transfer RNAs, including tRNA(Thr)(UGU) and tRNA(Arg)(CCU) 12. This modification requires prior N6-threonylcarbamoylation (t6A37) by the EKC/KEOPS complex as a prerequisite 2. METTL2A functions within a subfamily of m3C methyltransferases that employ mutually exclusive substrate selection, with METTL2A preferentially modifying threonine tRNAs while METTL6 targets serine tRNAs 23. m3C32 modifications regulate translation of specific codon-biased mRNAs, particularly those enriched in AGU codons encoding cell cycle and DNA repair proteins 3. Beyond canonical tRNA substrates, METTL2A deposits m3C marks in polyadenylated mRNAs and mitochondrial RNAs, enriched within CC motifs and coding sequences 4. Clinically, METTL2A is frequently amplified (~7%) in breast invasive carcinoma and associated with poor overall survival, functioning as a potential oncogene through activation of DNA synthesis and proliferation pathways 5. METTL2A upregulation also correlates with poor prognosis in pancreatic cancer and is essential for pancreatic cancer cell proliferation 4.