METTL3 and type 2 diabetes mellitus: On the other hand, methylglyoxal (a precursor of the advanced glycation end product) treatment of β-cells downregulated the METTL3 level, affecting MAFA mRNA and protein levels and decreasing GSIS (40).In addition, a study illustrating the lack of WTAP in the T2D pancreas deserves our attention (41).