METTL14, is also named as Methyltransferase-like protein 14 or KIAA1627, is a 456 amino acid protein, which belongs to the MT-A70-like family and localized in the nucleus. The METTL3-METTL14 heterodimer forms a N6-methyltransferase complex that methylates adenosine residues of some mRNAs and regulates the circadian clock and differentiation of embryonic stem cells. N6-methyladenosine (m6A), which takes place at the 5'-[AG]GAC-3' consensus sites of some mRNAs, plays a role in the efficiency of mRNA splicing, processing and mRNA stability. M6A regulates the length of the circadian clock: acts as a early pace-setter in the circadian loop.