Since we previously did not observe similar size and growth phenotypes in S. cerevisiae, C. elegans or D. melanogaster upon NSUN5 depletion (12), we first aimed to confirm that human NSUN5 methyltransferase activity is indeed directed against a specific cytosine of 28S rRNA, as previously hypothesized in literature (10,11,35) and shown in yeast, worms and human glioma cells (12,14,15). This evidence concerns the gene NSUN5 and central nervous system cancer.