2OG oxygenases are also involved in the regulation of RNA; thus, JMJD6 is proposed to be involved in the regulation of mRNA splicing by catalysing hydroxylation of splicing factors40, and in animals, the fat mass and obesity protein (FTO) and AlkB homologue 5 (ALKBH5) are N6-methyladenine hydroxylases/demethylases, and TWY5 and ALKBH8 hydroxylate the anticodon loops of some tRNAs2,28,39. Here, JMJD6 is linked to obesity due to melanocortin 4 receptor deficiency.